Defendant David Kysar entered a conditional plea of guilty to a charge of robbery pursuant to I.C.R. 11(a)(2), reserving the right to review certain adverse pretrial rulings. Kysar appeals the trial court’s denial of separate motions to suppress evidence and to dismiss the information for failure to hold a speedy trial. Kysar also appeals his sentence. We affirm.
I
SUPPRESSION OF EVIDENCE
First we address Kysar’s appeal of the trial court’s denial of his motion to suppress evidence. Kysar asserts that the police had no probable cause to arrest him, that the arrest and interrogation were illegal and that any evidence obtained from him should be suppressed. Kysar also argues that a “show up” conducted prior to the arrest was impermissibly suggestive and that any identification testimony and evidence stemming from it should be suppressed. Finally, Kysar challenges the use of all written and oral statements made by him after his arrest on the grounds that they were taken in violation of the Miranda rule, and that he did not voluntarily and knowingly make those statements.
A.
Probable Cause
We first address Kysar’s claim that the police had no probable cause to arrest him. A peace officer may make a warrant-less arrest when a felony has been committed and “he has reasonable cause for believing the person arrested to have committed it.” I.C. § 19-603. Reasonable or probable cause for an arrest exists where the officer possesses information that would lead a person of ordinary care and prudence to believe or entertain an honest and strong suspicion that the person arrested is guilty. State v. Alger, 100 Idaho 675, 603 P.2d 1009 (1979); State v. Cook, 106 Idaho 209, 677 P.2d 522 (Ct.App.1984). In evaluating a police officer’s determination of probable cause in the field, a court must take into account “the factual and practical considerations of everyday life on which reasonable and prudent men, not legal technicians, act.” Brinegar v. United States, 338 U.S. 160, 175, 69 S.Ct. 1302, 1310, 93 L.Ed. 1879, 1890 (1949); State v. Alger, 100 Idaho 675, 677, 603 P.2d 1009, 1011 (1979); State v. Cook, 106 Idaho 209, 215, 677 P.2d 522, 528 (Ct.App.1984). In determining whether there is probable cause for an arrest, an officer is entitled to draw reasonable inferences from the available information in light of the knowledge that he has gained from his previous experience and training. United States v. Ortiz, 422 U.S. 891, 95 S.Ct. 2585, 45 L.Ed.2d 623 (1975); United States v. Brignoni-Ponce, 422 U.S. 873, 95 S.Ct. 2574, 45 L.Ed.2d 607 (1975); Terry v. Ohio, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968).
*994We conclude that the record contains sufficient evidence to support the trial court’s finding that the police officers had reasonable cause to arrest the defendant. Shortly before 9:30 p.m. on February 4,1987, two individuals wielding knives robbed a Pizza Hut restaurant in Idaho Falls. They took between $558 and $609. The robbers’ faces were covered. Only three Pizza Hut employees were present, one of whom apparently was able to report the robbery while it was in progress. Officer Kevan Vanleuven responded to the report and arrived at the Pizza Hut within a minute after the robbers had fled the scene. Officer Vanleuven was told at the scene that the two robbers had fled northeast on foot in the direction of Hansen Avenue and climbed over a fence at the north end of the parking lot. Officer Vanleuven then radioed a hurried description of the robbers given by Bob Rudolph, one of the employees. The report provided the following details: two individuals on foot, both wearing Levi’s and white tennis shoes, one wearing a green Army fatigue-type jacket with a U.S. Army patch on the front pocket, the other wearing a dark hooded jacket. Shortly after Officer Vanleuven radioed his report, the dispatcher radioed a citizen’s report of persons running on Hansen Avenue, getting into a small yellow Honda, and speeding down Raymond Drive. (Hansen Avenue runs north from the Pizza Hut and comes to a finish at Raymond Drive after curving slightly to the east. The section of Raymond Drive which the car sped down curves southeast, finishing at Skyline Drive which runs north-south.)
Officer Brent Guymon heard the radio reports and drove west along Pancheri Drive toward the scene of the crime in order to close off a possible escape route (Skyline Drive). As he approached Skyline Drive, Officer Guymon spotted a small yellow “Honda looking” car (actually, a Ford Fiesta) with two persons inside. The car was turning quickly left (east) onto Pancheri Drive. His observation came 3 or 3V2 minutes after the initial robbery report. Officer Guymon testified that it would take between 2 and 3 minutes to drive from the Pizza Hut to the intersection at Pancheri Drive and Skyline Drive. After the small yellow car passed him, Officer Guymon turned around and followed, eventually ending up in an alleyway near a residence.
After coming to a stop in the alleyway, David Kysar and his twin brother Dale got out of the yellow Fiesta. Officer Guymon then detained them for an investigation. Both wore Levi’s and white tennis shoes. Dale wore a green Army fatigue-type jacket with a U.S. Army patch on the pocket. David wore a black T-shirt with no sleeves. Sgt. James Codding, who backed up Officer Guymon, testified that it was very cold that night (February 4, 1987).
While Officer Guymon may have possessed sufficient information at that point to strongly suspect the Kysars’ guilt, he did not arrest them until after they had been positively identified by two Pizza Hut employees in a “show up” conducted outside the apartment. Shortly after the detention began, Officer Vanleuven brought the employees, Rudolph and Dorae Bur-dick, to the scene. With their faces covered by jackets, the Kysars were placed within five or six feet of the eyewitnesses. Burdick identified Dale as being one robber, based on his green Army fatigue-type jacket. Rudolph said the suspects were of the same build as the robbers and that David tied the black shoelaces in his white tennis shoes the same unique way as the robber. Sgt. Codding then arrested the two Kysar brothers. Based upon this identification, which we find was not impermissibly suggestive (see discussion in Part 1(B)), and the available information, including eyewitness reports at the Pizza Hut, the radio dispatch of the citizen’s report, and Officer Guymon’s observation from his car, we hold that the police had reasonable cause to arrest David Kysar.
B.
“Show Up”
Evidence of an out-of-court identification shall be suppressed only where, under the totality of the circumstances, the identification procedure was so impermissi*995bly suggestive as to give rise to a very substantial likelihood of mis-identification. Neil v. Biggers, 409 U.S. 188, 93 S.Ct. 375, 34 L.Ed.2d 401 (1972). “[R]eliahility is the linchpin in determining the admissibility of identification testimony____” Manson v. Brathwaite, 432 U.S. 98, 114, 97 S.Ct. 2243, 2253, 53 L.Ed.2d 140, 154 (1977). Factors to be considered in determining whether the identification is sufficiently reliable include: (1) the opportunity of the witness to view the criminal at the time of the crime; (2) the witness’s degree of attention; (3) the accuracy of the witness’s prior description of the criminal; (4) the level of certainty demonstrated at the identification; and (5) the length of time between the crime and the identification. Manson v. Brathwaite, 432 U.S. 98, 97 S.Ct. 2243, 53 L.Ed.2d 140 (1977); State v. Hoisington, 104 Idaho 153, 657 P.2d 17 (1983); State v. Edwards, 109 Idaho 501, 708 P.2d 906 (Ct.App.1985).
Kysar’s primary complaint is that the “show up” identification was unreliable because it was conducted in a suggestive manner in two respects. First, Kysar claims that covering his head with a jacket was unnecessarily and impermissibly suggestive. However, as the trial court found, the “jacket was held so that the witnesses could not see [the Kysars’] faces but viewed their bodies and clothing from the shoulders down.” As previously mentioned, the robbers’ faces were covered while in the Pizza Hut. The police did not want the identification to be influenced by the Kysars’ facial appearance. This covering up was not impermissibly suggestive.
Second, Kysar insists that he and his brother were handcuffed while the eyewitnesses were present so that they would resemble guilty criminals. However, police officers present testified that handcuffs were removed before the “show up.” Testimony of Sgt. Codding, Officer Guymon, Officer Yanleuven and Detective Forrest differed with Kysar’s version. For example, Sgt. Codding testified that he had the handcuffs removed because he “wanted to make it as natural as possible’ even though Detective David Forrest said he wasn’t really comfortable with the idea because of potential danger. In considering the testimony presented, the trial court as trier of fact did not find that the Kysars were handcuffed, but only that “a jacket was held so that the witnesses could not see their faces____” Unlike an appellate court, the trial court as trier of fact has a special opportunity to judge the credibility of witnesses who appear personally before it. It is widely accepted law that
[t]he triers of the facts may accept all of a witness’ testimony, may reject it all, or may accept part and reject part, in accordance with the facts and circumstances bearing on the credibility of the witness.
98 C.J.S. Witnesses § 458 (1957); see Rasmussen v. Martin, 104 Idaho 401, 659 P.2d 155 (Ct.App.1983); Idaho Appellate Handbook, 3.3, Idaho Law Foundation (1985); I.R.C.P. 52(a). Furthermore, the trial court’s findings of fact shall not be disturbed on appeal unless unsupported by substantial competent evidence. State v. Snowden, 79 Idaho 266, 313 P.2d 706 (1957); State v. Curtis, 106 Idaho 483, 680 P.2d 1383 (Ct.App.1984).1 Although Kysar gave conflicting testimony, there is substantial competent evidence in the record that the Kysars were not handcuffed during the “show up.” Furthermore, the following evidence supports a finding that the Biggers reliability factors were met: (1) Rudolph and Burdick were in the Pizza Hut watching as the robbery took place; (2) Rudolph and Burdick got a good look at the robbers; (3) the witnesses’ descriptions to the police of the robbers’ clothing were matched with the clothing worn by the Kysar brothers; (4) the witnesses gave positive identifications, citing specific aspects of the suspects’ clothing which led them to their conclusions; and (5) the “show up” occurred approximately an hour after the robbery.
The trial court’s findings of fact were based on substantial competent evidence, *996and the Biggers reliability factors were met. We therefore affirm the trial court’s finding that the “show up” was not conducted in an impermissibly suggestive manner.
C.
Miranda
When an accused person in custody has invoked his right to counsel under Miranda v. Arizona, 384 U.S. 436, 86 S.Ct. 1602, 16 L.Ed.2d 694 (1966), he is not subject to further interrogation until counsel has been made available to him, unless he waives his earlier request for counsel and himself initiates any dialogue. Edwards v. Arizona, 451 U.S. 477, 101 S.Ct. 1880, 68 L.Ed.2d 378 (1981). His responses to further questions in the absence of counsel may be admitted as evidence only when it is shown that he initiated further discussions with the police and that he knowingly and intelligently waived his right to counsel which he earlier invoked. Smith v. Illinois, 469 U.S. 91, 105 S.Ct. 490, 83 L.Ed.2d 488 (1984); State v. Culbertson, 105 Idaho 128, 666 P.2d 1139 (1983); State v. Blevins, 108 Idaho 239, 697 P.2d 1253 (Ct.App.1985). Proof of such initiation must be established by a preponderance of the evidence. State v. Culbertson, 105 Idaho 128, 666 P.2d 1139 (1983).
Here, both Kysar and the State agree that Kysar invoked his right to counsel after being told that he and his brother were suspected of robbery. Aside from this agreed fact, Kysar’s version of the facts differs significantly from that of the State.
Kysar asserts that after invoking his right to counsel the police nevertheless used various improper tactics to extract an involuntary confession which amounted to an inherently coercive custodial interrogation warranting suppression. Such tactics allegedly included: lengthy detention before booking (allegedly five hours); relocation at police headquarters into three separate rooms; handcuffing to tables in each room; failure to provide food or sleep; and police intimidation and threats.
Kysar testified that after being placed initially into a small room, he was taken into a larger room where Officer Guymon was writing a report. Kysar testified:
A. I sat there for a long time and the detective [Forrest] then came in and he told me that he would be right with me, that he was about finished with my brother. He then left the room.
Q. [By defense counsel] Then what happened?
A. Then I was sitting there, I was becoming uncomfortable, I reached into my pants and pulled out some money. The first officer at the scene asked me what it was and I said it was some money and he took it from me.
Officer Guymon testified:
A. Well, I was just sitting there typing and he asked, “How is it going?”
I answered, “Probably better than you.” We just sat there quiet for a short [time] and that is when he asked how it was going and I replied, “A lot better than you.”
About five, ten minutes later he reels back and sticks his hand down his pants and alerted me, what is going on here, and pulled out a white plastic bag and tossed it on the table and said, “This may help.”
Q. [By the prosecutor] Prior to that time had you asked him any questions in the report room?
A. No. Just a statement, “Probably better than you.” I didn’t ask him any questions, just basically typing my report and watching him.
The bag contained over $500 in cash.
Kysar testified further that after he had handed the bag of cash over to Officer Guymon he was then taken into another room.
A. He [Detective Forrest] then took me back to the room that I hadn’t been in, but it was a smaller room that had a two-way mirror on it. I believe it was one next to the one I had been placed in the first time.
Q. [By defense counsel] And what happened there?
*997A. Then he came in — well, he took me in there and he asked me if I would like a cup of coffee and I replied “yes”. He left and came back.
He then asked me if I wanted to talk to him about this case and I said, “No. I want to see a lawyer.”
He then told me if I cooperated with him that he would work out something with the DA and the judge where I wouldn’t go to prison, I would go to Cottonwood for cooperating and stuff. I then told him I really didn’t know what I should be doing right at this point.
Q. How were you feeling at that point in time?
A. I was feeling — I was scared, you know, nervous.
Q. This was the same detective that talked to you in the blue car?
A. Yes.
Q. Eventually I take it he brought you some papers to sign and fill out?
A. No, he didn’t. He put me in this room, asked me if I wanted a cup of coffee. He then left the room, brought me back my cup of coffee. I already had cigarettes. He then asked me if I wanted to discuss this case with him and I said “no”. I specifically said, “No, I want to see my lawyer first.”
He then told me if I cooperated with him that he would talk to the DA and the judge and work out something for me.
Q. Then he went away again?
A. He was still in the room. I told him that I didn’t exactly know what I wanted to do yet, I wanted to think about things. He then became defensive with me. He then told me, “Your brother has written a statement, he has told us you were involved and we know everything. There is no way you can weasel out of it.”
Q. Apparently you did sign a statement or something like that?
A. Yes, I did.
Q. Is that after all of the events you have described up until now?
A. Right after he became angry with me and told me that there was no way I was going to get out of it I said, “What is it you want me to do?”
He then told me that he wanted me to write a statement. He gave me a piece of paper, he left the room. I finished the statement, he came back. He read it over and he asked me to sign it and I signed it. He then left again and then came back and at this time he reached into a folder like thing and pulled some papers out, like a briefcase, leather briefcase or folder, paper folder.
He then told me that he wanted me to sign it — I asked him what it was and he said that it was a piece of paper, that I had been read my rights.
Q. Did you sign that?
A. I signed it.
Q. Of course, he had read you your rights much earlier?
A. The first time they read me my rights was after I was identified.
Q. Did you ask the detective to come back and talk with you?
A. No, I didn’t.
Q. Did you tell some other officer you wanted to talk to the detective?
A. No, I didn’t. The detective came in and said he would be right with me, he would be finished right away.
Q. At what point were you booked into the jail?
A. After I had signed the paper advising me that my rights had been read, then he asked me some questions about some other armed robberies. He told me that if I copped up to them he would only charge me with one. He then asked me about some milk, you know, nothing about either of them. He then took me out and an officer took me to jail.”
Detective Forrest’s testimony is entirely different from Kysar’s version of what occurred. Detective Forrest’s testimony was supported by a tape recording of the interview made by the officer, apparently unbeknownst to Kysar, which shows that Kysar’s testimony was patently false in many respects. After taking a statement from Kysar’s brother, Detective Forrest testified that he was told by an officer that David Kysar wanted to speak with him. Detec*998tive Forrest then entered the interview room, the third room to which Kysar had been taken. The following is a transcript of the tape recorded conversation which took place:
Forrest: The sergeant says that you requested to talk to me now.
Kysar: Yeah.
Forrest: Okay. Before you say anything, you’ve indicated before that you wished to talk to an attorney, which, you know, that’s no problem. You do have that right to talk to one. Are you changing your mind now and wish to talk to me without an attorney?
Kysar: Yeah [unintelligible].
Forrest: What did you say?
Kysar: Yes.
Forrest: Oh, okay. I didn’t understand what the deal was here for sure. Okay. I’ll read this form to you here. You do have a right to remain silent and anything you say can and will be used against you in a court of law. You have the right to talk to a lawyer before we talk to you and have him present while we talk to you. If you cannot afford to hire a lawyer, one will be appointed to represent you before any questioning free of charge. You can decide at any time to use these rights and not answer any questions or make any statements. Do you understand each of these rights I’ve explained to you?
Kysar: Yes.
Forrest: Do you wish to discuss this case with me at this time?
Kysar: Yes.
Forrest: Do you wish to have an attorney present?
Kysar: No.
Forrest: Okay. Your signature right here.
(Pause.)
Forrest: Why don't you tell me what it was you wanted to discuss with me. Kysar: Any of your questions [unintelligible].
Forrest: Why don't you just start from the beginning and tell me what happened.
This foregoing transcript from the tape directly contradicts Kysar’s testimony in many respects. The low key nature of the conversation recorded was unlike the intimidating confrontation testified to by Kysar. Both the testimony of Detective Forrest and the tape demonstrate that Kysar’s testimony concerning the discussion he had with Detective Forrest was shown to be false and unreliable. The trial court was entirely justified in relying on the testimony of the police officers, and disregarding the testimony of Kysar in determining whether Kysar had voluntarily initiated discussions with the police officers, thereby waiving his right to counsel. Edwards v. Arizona, 451 U.S. 477, 101 S.Ct. 1880, 68 L.Ed.2d 378 (1981). It has been the universally accepted rule of this Court, and the other courts in the United States, that when a witness has been shown to have testified falsely, a trier of fact is entitled to disregard the testimony of that witness. Smith v. Howard, 76 Idaho 235, 240, 280 P.2d 1060, 1063 (1955) (“While there was no direct contradiction of parts of the witness’ testimony, the witness was sufficiently impeached and his testimony so contradictory in itself, that the trial court was warranted in disregarding his evidence.”). See also 98 C.J.S. Witnesses § 458 (1957).2 Here, the trial court weighed the credibility of the witnesses and resolved the conflict in favor of the State, finding that Kysar made a valid waiver of his right to have counsel present during interrogation by initiating, without reservation, the interrogation.
From the evidence submitted by the State, the trial court found that Kysar was not subject to coercive tactics designed to extract a confession, and that the officers originally ceased questioning Kysar as soon as he invoked his right to counsel. Without prompting, Kysar handed over the money apparently taken in the robbery. Not until Kysar initiated further discus*999sion, and had again been given oral and written advice of his rights under Miranda, did interrogation commence. The record indicates that Kysar arrived at the station at about 10:45 or 10:50 p.m. and that, following his discussion with Detective Forrest, he was booked into jail at 12:42 a.m. During that less than two hour period, the police continued searching for the shirt or jacket that Kysar had apparently discarded after fleeing the Pizza Hut on that cold night. Police wanted to see if the garment, if found, fit him. Police also wanted to take their own photographs of the robbery suspects, and indicated that it could be difficult to get defendants back into the station for this purpose once they had been placed in the jail. It is not improper police conduct to handcuff to a table someone arrested for robbery by knife-point, nor is it improper police conduct to relocate someone twice before booking. Because Kysar did not eat or sleep during the less than two hour period does not make his subsequent waiver invalid. Kysar was given coffee and cigarettes as he requested. On the basis of the foregoing facts found by the trial court, which are supported by the tape and the testimony from Detective Forrest and the other officers, we affirm the trial court’s finding that Kysar made a knowing and voluntary waiver of his rights under Miranda, and that his statements to the police were not taken in violation of his rights under the Constitution.
II
SPEEDY TRIAL
Kysar argues that his statutory right to a speedy trial was violated because a trial was not held within six months from the day the information was filed against him. I.C. § 19-3501.3 However, where a trial is postponed upon application of the defendant, the six-month deadline in I.C. § 19-3501 is not applicable. Because Kysar successfully moved to vacate a May 11, 1987, trial date, he waived his statutory speedy trial right under I.C. § 19-3501.4
Ill
SENTENCING
Kysar claims the sentencing court abused its discretion in imposing an unreasonable sentence, four to ten years in prison. Kysar argues that the sentencing court should have devised a plan that combined incarceration with meaningful treatment for stress stemming from attention deficit disorder.
Kysar could have received a life sentence for the crime of robbery. I.C. § 18-6503. Because his sentence was within the statutory maximum, we will uphold it unless the sentencing court abused its discretion. State v. Nice, 103 Idaho 89, 645 P.2d 323 (1982). A sentence may represent such an abuse if it is shown to be unreasonable upon the facts of the case. Id. Here, because the court specified that the minimum term of confinement would be four years, four years is the term of confinement for the purpose of appellate review. See State v. Maxfield, 115 Idaho 910, 771 P.2d 928 (Ct.App.1989); State v. Sanchez, 115 Idaho 776, 769 P.2d 1148 (Ct.App.1989). We must determine whether a four-year *1000prison term is reasonable when viewed in light of the nature of the offense and the character of the offender.
Kysar and his brother were sentenced for taking money from Pizza Hut employees by threatening them with knives. This was a very serious crime. The record indicates that although Kysar was only nineteen years old when he committed the robbery, he had an extensive criminal record consisting of other felony offenses (theft and aggravated assault) and misdemeanors (obstructing justice, assault, disorderly conduct and criminal mischief). Kysar also pleaded guilty to assaulting a law enforcement officer while in jail awaiting disposition of the present case. Extensive testimony at the sentencing hearing concerned Kysar’s background, growing up in an abusive household, his present difficulty in obtaining employment and his psychological difficulty, attention deficit disorder. While this evidence may help explain how Kysar became the person that he is, it does not change the fact that he is a danger to society. However, the sentencing court took this background evidence into account and issued an order under I.C. § 19-2523 authorizing treatment for Kysar’s psychological problems during his incarceration. Having considered the record, we conclude that the sentence is not excessive and that the sentencing court did not abuse its discretion. Accordingly, Kysar’s sentence is affirmed.
We affirm the judgment of conviction and sentence imposed.
JOHNSON, BOYLE and McDEVITT, JJ., concur.. Under I.C.R. 12(e) the trial court was not even required to make factual findings unless requested by any party. State v. Kirkwood, 110 Idaho 97, 714 P.2d 66 (Ct.App.1986).
. As an appellate court we do not have the same opportunity to assess the witness’s credibility and demeanor on the stand, and therefore we are bound by the trial court’s findings of fact unless they are unsupported by substantial competent evidence. State v. Snowden, 79 Idaho 266, 313 P.2d 706 (1957); State v. Curtis, 106 Idaho 483, 680 P.2d 1383 (Ct.App.1984).
. 19-3501. When action may be dismissed.—
The court, unless good cause to the contrary is shown, must order the prosecution or indictment to be dismissed, in the following cases:
2. If a defendant, whose trial has not been postponed upon his application, is not brought to trial within six (6) months from the date that the indictment or information is filed with the court.
. Here, an information was filed against Kysar sometime between February 6, 1987 (the date of the order binding over), and February 11, 1987 (the arraignment date). Several trial dates were set (and not met) before Kysar entered a conditional guilty plea on August 25, 1987, which was six days before the latest trial was set on August 31, 1987 (six months, 25 days, after the order binding over). We need not address the issue of whether a delay in bringing Kysar’s case to trial, resulting from the trial court’s administrative schedule and not the prosecution, is not a per se violation of I.C. § 19-3501, State v. Sindak, 116 Idaho 185, 774 P.2d 895 (1989), because here at least one of the trial dates was vacated upon the defendant's motion.