*56OPINION OF THE COURT
EAGEN, Justice.Charles Coley was convicted by a jury in Philadelphia of murder in the first degree, attempted robbery and criminal conspiracy. Subsequently, the trial court ordered a new trial. The Commonwealth filed an appeal in this Court from the order granting a new trial as it affected the murder conviction.1 An appeal was filed in the Superior Court from the order as it affected the robbery and conspiracy convictions. The last mentioned appeal was later transferred here. Both appeals were consolidated for argument in this Court and pose the same legal issues.
At trial the Commonwealth introduced into evidence over timely objection an executed handprinted account of an incriminating oral statement given by Coley to the police.2 Following the filing of a motion for a new trial, the trial court concluded that evidentiary use at trial of Coley’s incriminating statement was proscribed by Rule 130 of the Pennsylvania Rules of Criminal Procedure, and hence, a new trial was required.3 Commonwealth v. Futch, 447 Pa. 389, 290 A.2d 417 (1972). The trial court’s conclusion that the admission of evidence of Coley’s incriminating statement at trial was error was based *57solely on this Court’s opinion in Commonwealth v. Johnson, 459 Pa. 171, 327 A.2d 618 (1974).
We believe the lower court’s reliance on Commonwealth v. Johnson, supra, was inappropriate. Further, since we have determined that no violation of the Futch rule exists under the circumstances of this case, we reverse.
The relevant facts upon which we have made our determination are as follows:
On October 20, 1973, a robbery and fatal shooting occurred at the Kesmon Hotel in Philadelphia. [Hereinafter hotel robbery.] On October 28, 1973, two men attempted a robbery at the Mt. Carmel Baptist Church in Philadelphia.4 [Hereinafter church robbery.] During the church robbery, a police officer, Detective Ross, was shot, though not fatally. Emmett Barrett was quickly apprehended by police following the church robbery. A .32 caliber handgun was recovered by police at that time. The other participant in the church robbery escaped capture. As a result of statements made by Barrett to police concerning the church robbery, a warrant for Coley’s arrest was issued for his participation in the church robbery. Inter alia, Barrett told the police he acquired the gun from Coley sometime earlier.
Sometime subsequent to October 28, 1973 but prior to Coley’s arrest, a ballistic test of the bullets recovered from the body of Caldwell, the person who was fatally shot in the hotel robbery, and from Detective Ross indicated that both bullets were fired from the same gun. But the police never used this information to obtain a warrant for the arrest of Coley for the hotel robbery.
Between October 28, 1973 and November 30, 1973, the date on which Coley was arrested, the Philadelphia police learned that Coley had a fiancee in Virginia. The police *58then supplied the Federal Bureau of Investigation with this information. Pursuant to this information, a federal warrant for Coley’s arrest was issued for flight to avoid prosecution. On November 30, 1973, Coley surrendered to federal authorities in Philadelphia. An arraignment was held in a federal magistrate’s court at which time the federal officials withdrew the federal charges against Coley. At that arraignment Coley had counsel, apparently supplied by federal officials.
At 12:00 p. m. on November 30, 1973, Coley was transferred to the custody of Philadelphia police by federal officials. The Philadelphia police arrested Coley pursuant to the outstanding warrant for his participation in the church robbery and pursuant to facts sufficient to give the officers probable cause to arrest for participation in the hotel robbery. For present purposes we can assume Coley was arrested without a warrant for his participation-in the hotel robbery only.5 Moreover, the police informed Coley, at the time of his arrest, of the reason for his arrest, that is, his participation in the hotel robbery and fatal shooting of Caldwell.
Coley was then taken to the Police Administration Building where he arrived at 2:45 p. m. on November 30, 1973. At 2:55 p. m., an interview with Coley was conducted by Detective Cleary, one of the two arresting officers. Coley was given his Miranda warnings at this time and affirmatively indicated he understood his rights. He *59expressed a willingness to answer questions but denied any involvement in the hotel robbery. This interview was concluded at 4:25 p. m. Between 4:25 and 5:10 p. m., Coley was left alone. From 5:10 to 5:20 p. m., he was taken to the men’s room and given water. At 5:20 p. m. until 6:05 p. m., Detective Cleary again interviewed Coley. Coley again denied involvement in the hotel robbery.
At 6:05 p. m., Lt. Patterson, the other arresting officer, entered the polygraph room where Coley was being interviewed. Cleary left and Patterson gave Coley his Miranda warnings. Patterson interviewed Coley from 6:05 p. m. until 6:30 p. m. and during this time Coley made an oral admission of involvement in the hotel robbery. Lt. Patterson then left the room and told Detective Cleary that Coley would give him an account of the hotel robbery.
At 6:30 p. m., Cleary entered the room and again gave Coley his Miranda warnings; nonetheless, Coley proceeded to give Cleary a statement admitting his participation in the hotel robbery.6 As it was given, Coley recorded the statement in handprinting. When completed, it was signed by Coley.
Disregarding the period of time used in the transportation of Coley from the custody of the federal authorities to the City Police Administration Building, which was obviously necessary and free from coerciveness, the instant case involves a delay of three hours and thirty-five minutes during which period two interviews were conducted. The two interviews totaled two hours and forty minutes. The first interview lasted for one hour and thirty minutes; the second interview, during which Coley incriminated himself, lasted one hour and ten minutes. The interviews were interrupted by a fifty-five minute interval during which Coley was allowed to take care of his physical needs and to rest.
*60Moreover, the suppression hearing court found on adequate and credible evidence that Coley was not under the influence of alcohol or narcotics, that he understood his constitutional rights and knowingly, willingly and voluntarily waived them, that he was under no mental or physical impairment. Coley was twenty-one years old at the time of his arrest and had an eleventh grade education. Finally, the suppression hearing court concluded that Coley’s admissions were voluntary.
The trial court’s reliance on Commonwealth v. Johnson, supra, was inappropriate because facts present therein and important to the decision in the case are not present here. The trial court was apparently influenced by the fact that the instant case involved a delay of three hours and thirty-five minutes or a period approximating the four hour delay period in Johnson, supra. But the mere comparison of time periods is not a sufficient inquiry. The Futch rule has as its purpose the elimination of circumstances which are coercive in nature, including constant and prolonged interrogation. See Commonwealth v. Young, 460 Pa. 598, 334 A.2d 252 (1975). See also Commonwealth v. Bryant, 461 Pa. 3, 334 A.2d 603 (1975) (Opinion in Support of Affirmance), and Commonwealth v. Hamilton, 460 Pa. 686, 334 A.2d 588 (1975) (Opinion in Support of Affirmance). Thus, the Futch issue necessitates an examination of all the facts to determine what degree of coerciveness exists in any given case. This is not to say that the three-pronged inquiry outlined in Commonwealth v. Williams, 455 Pa. 569, 319 A.2d 419 (1974), is not the formula to be used in determining if there was a violation of the Futch holding. But it is a mere formula designed to effectuate a purpose and only when the purpose of Futch, namely, to prevent an accused from being subjected to coercive influences and circumstances, is advanced will Futch be applied to suppress a confession.
*61The purpose of Futch was advanced in Johnson, supra, because there were attending circumstances which persuaded a majority of the Court that a great degree of coerciveness existed. Therein the accused was only fourteen years of age and was questioned without the presence of or prior consultation with his parents or counsel, during the late hours of night and on into the early hours of morning. Such coercive circumstances which were the operative facts in the application of Futch in Johnson are not present here. Thus, Johnson, supra, served the purpose of the Futch rule but it did so because of facts not present in this case and therefore, Johnson, supra, is not determinative here.
Having distinguished Johnson, supra, and reiterated the purpose of the Futch rule, and with that purpose in mind, we now turn to the three-pronged test and apply it to the instant case. In order for evidence to be suppressed under Futch there must be (1) an unnecessary delay, (2) evidence obtained from the accused which is a product of the delay, that is, there must be a “nexus” between the delay and the evidence, and (3) the evidence must be prejudicial. See Commonwealth v. Williams, supra, and Commonwealth v. Young, supra. The instant case requires a consideration of the first two requirements.
We thus turn to the initial question of whether the delay here was “unnecessary.” A review of the cases involving this question indicates that the shortest period of time which has ever resulted in the suppression of evidence was four hours in Commonwealth v. Johnson, supra. But we have already pointed out the important differences between that case and this one. Here the delay was only three hours and thirty-five minutes. Coley willingly waived his Miranda rights and agreed to be questioned for a period of time. The agreeing to questioning by the police necessitated the delay. Thus, because the period of time is so short and because Coley *62agreed to be questioned, we do not think this delay can be considered “unnecessary.”
Our conclusion is supported by other decisions of the Court, particularly Commonwealth v. Edwards, 463 Pa. 129, 344 A.2d 460 (1975); Commonwealth v. Young, supra, and Commonwealth v. Whitson, 461 Pa. 101, 334 A. 2d 653 (1975).
In Edwards, the evidentiary use at trial of the defendant’s inculpatory statement was asserted as error and in violation of the Futch rule because of the lapse of five hours between the time of arrest and the giving of the inculpatory statement. This Court unanimously rejected this argument and affirmed the conviction in a “per curiam” order. In Young, the defendant was arrested at 7:15 a. m. and initially incriminated himself at 1:15 p. m. This Court ruled evidence of the incriminations was properly admitted at trial and no violation of the Futch rule occurred. In Whitson, there was a delay of four hours between the arrest and the self-incriminations, but this Court held the Futch rule did not proscribe evidence of the self-incriminations at trial.
Even though we have concluded that the delay was not unnecessary, we shall examine the nexus question because our conclusion, from which follows our view that the purpose of Futch would not be advanced by its application here, is further supported by such an examination. The Futch rule is not inflexible and although we make distinctions between the nexus and the unnecessary delay inquiries, both are interrelated because of the purpose of the Futch rule. Our concern is not centered so much on the results under any particular branch of the three-pronged inquiry as it is with whether or not the purpose of Futch will or will not be advanced by its application in any given case. Both branches, that is, the delay and nexus branches, of the three-pronged inquiry aid in determining whether coercive circumstances exist in a sufficient degree such that the application of the Futch rule will ef*63fectuate its purpose. Just as the length of the delay aids in the determination of whether the delay is necessary, it also aids in the determination of whether a nexus exists. So too the circumstances surrounding a delay aid in the determination of whether a delay is necessary, just as they aid in determining if a nexus exists. Commonwealth v. Boone, 467 Pa. —, 354 A.2d 898 (1975). See also Comment: Pennsylvania Supreme Court Review, 1974, 58 Temple L.Rev. 527, 635 (1975).
The Comment points out that the three-pronged inquiry we use should not be considered an inflexible or mechanical device or the determinations made by this Court would have to be considered erratic and unpredictable. Rather, as suggested in the Comment, our three-pronged inquiry is merely a method of analysis to examine the totality of the circumstances to determine if coercion in a sufficient degree exists to warrant rejection of the confession. Our emphasis on the delay is merely a recognition of the fact that a delay in and of itself, if sufficiently long, when viewed in relationship to the accused, including such factors as age and intelligence, may cause a sufficient amount of psychological coercion to result in an involuntary confession. Our inquiries into such matters as why the police allowed a delay, Commonwealth v. Whitson, supra, merely recognize the obvious reality that some delays and thus some psychological coercion are, as a practical matter, absolutely necessary without regard to the effect on a given accused. But the mere fact that the police offer no excuse for a short delay does not lead to the conclusion that a delay was unnecessary and therefore sufficiently coercive to warrant the application of Futch. Ultimately we look to the totality of the circumstances to determine coercive circumstances, including the length of a delay and the effect on the accused and then we evaluate the situation as a question of degree.
*64Thus, with the view that the necessity of a delay and the nexus between a delay and confession are interrelated, we turn to the question of a nexus. The nexus between the delay and confession is established only where the accused proves that the confession was a product of the delay, that is, the delay is shown to be a contributing factor in obtaining the confession. Commonwealth v. Young, 460 Pa. 598, 384 A.2d 252 (1975); Commonwealth v. Rowe, supra. Again, the totality of the circumstances must be examined to determine the degree of coercion in order to make this determination.
Coley was given his Miranda warnings repeatedly. He voluntarily agreed to questioning. He was an adult and was questioned in the day time without any showing that he was tired or otherwise physically impaired. He was subjected to no threats or promises. Finally, Coley was of average intelligence and had an eleventh grade education.
Coley was not constantly subjected to questioning; rather, on the contrary, he was allowed to rest between interviews for almost an hour. Further, the total delay was only three hours and thirty-five minutes. Only two police officers, those who arrested Coley, questioned him.
Under these facts we are convinced this case is controlled by this Court’s decision in Commonwealth v. Young, supra, which involved an adult, rather than Commonwealth v. Johnson, supra, which involved a minor. In Young, supra, we ruled that no proof existed to establish the nexus between the delay and the confession. There the delay lasted six hours, two and one-half hours more than here; and the length of delay is always indicative of the existence or nonexistence of a nexus. Commonwealth v. Boone, supra. In Young, supra, the police questioned the accused in two sessions which were interrupted by a period of rest, as was Coley. There the accused was an adult, as was Coley at the time of his ar*65rest. No other coercive circumstances exist in this case.7 Thus, we conclude that no reasonable relationship exists between the delay and confession. Commonwealth v. Young, supra. And see Commonwealth v. Bryant, supra; Commonwealth v. Hamilton, supra, and Commonwealth v. Smith, 463 Pa. 393, 344 A.2d 889 (1975).
Having analyzed all the facts and circumstances, we hold that since the purpose of Futch, the elimination of coercive circumstances, including constant and prolonged interrogation, will not be advanced by the application of the rule, the Futch rule is inapplicable. It is fundamental that no rule of law should ever be applied unless the purpose for which it was developed will be served by its application in a given case.
Since we have concluded the admission into evidence of Coley’s incriminating statements was not a proper basis for the granting of a new trial, it is necessary to consider Coley’s alternative argument for a new trial. Coley argues that the trial judge lent undue strength to the Commonwealth’s case when he reviewed the evidence during his instructions to the jury. We need not reach the merits of Coley’s argument since it was not properly preserved for review by this Court.
Although counsel objected to the instructions to the jury on the grounds here asserted in compliance with *66Pa.R.Crim.P. 1119(b), he did not include this assignment of error in the post-verdict motion for a new trial. Further, even though counsel reserved the right to file additional reasons for a new trial after the record was transcribed, our review of the record discloses that no additional reasons were presented in writing to the trial court. Since the issue was not properly presented to the trial court, that is, by written post-verdict motion, it was not properly preserved for our review.8 Pa.R.Crim.P. 1123(a); Commonwealth v. Irwin, 460 Pa. 296, 333 A.2d 735 (1975); Commonwealth v. Blair, 460 Pa. 31, 331 A. 2d 213 (1975).
The order of the trial court granting a new trial is therefore reversed. The record is remanded to the trial court for the purpose of imposing sentence.
POMEROY and NIX, JJ., concur in the result. ROBERTS, J., filed a dissenting opinion in which MANDERINO, J., joined.. Since the issue involved is purely one of law the Commonwealth may appeal. See Commonwealth v. Melton, 402 Pa. 628, 168 A.2d 328 (1961).
. A pretrial motion to suppress this evidence was denied after an evidentiary hearing.
. An executed, typewritten confession given by Coley was also introduced into evidence but since the handprinted statement was the first to be obtained and since the typewritten statement was substantially the same as the handprinted one, we shall limit our analysis to the circumstances surrounding the handprinted statement Commonwealth v. Davis, 460 Pa. 644, 334 A.2d 275 (1975); Commonwealth v. Rowe, 459 Pa. 163, 327 A.2d 358 (1974).
. Coley’s conviction was a result of charges brought against him for his participation in the hotel robbery and fatal shooting, not for any involvement in the church robbery.
. Although the arrest warrant for the church robbery was still outstanding, subsequent events indicate the arresting officers were more interested in the hotel robbery. In its opinion granting a new trial, the trial court stated that Coley was arrested pursuant to the warrant. In his findings of fact from the suppression hearing, the hearing court judge stated nothing about the warrant but indicated that probable cause existed for Coley’s arrest for his participation in the hotel robbery. Because the record strongly indicates that Coley was indeed arrested for the hotel robbery, we shall assume he was arrested without a warrant. Moreover, the lower court’s finding that the arrest was based on probable cause is not now challenged, thus Coley’s arrest must be considered legal.
. The statement also contained references to the church robbery which are not here relevant.
. The testimony indicates that Coley was also confronted with the knowledge on the part of the police of the results of the ballistic test and Barrett’s statements between 5:20 p. m. and 6:30 p. m. The precise time cannot be determined because the lower court made no finding in this regard. The Commonwealth’s testimony indicates he was confronted with it by Lt. Patterson immediately before agreeing to confess. Coley testified that Detective Cleary informed him of it between 5:20 p. m. and 6:05 p. m. Even assuming Coley’s testimony is believed on this matter, the confrontation represents an added circumstance, which though not determinative in itself, Commonwealth v. Doamaral, 461 Pa. 517, 337 A. 2d 273 (1975); Commonwealth v. Abi-Ion Hanifah Bey, 462 Pa. 533, 341 A.2d 907 (1975), when considered with all the other circumstances mitigates against the delay itself being considered as sufficiently long to establish a nexus. See Commonwealth v. Fogan, 449 Pa. 552, 296 A.2d 755 (1972).
. Although oral motions have been deemed sufficient to preserve an issue for appeal where the relevant events occurred prior to our decision in Commonwealth v. Blair, supra, see Commonwealth v. Bailey, 463 Pa. 354, 344 A.2d 869 (1975), neither the record, nor the opinion of the trial court, nor Coley’s brief indicates in any way that the issue was brought before the trial court on oral motion following trial and conviction. As such the exception to our rule in Blair, supra, has no application here.