The instant appeal arises from appellant’s conviction of the crimes of escape,1 possession of instruments of escape,2 possession of an instrument of crime,3 and carrying a prohibited offensive weapon.4 Appellant was acquitted of the charges of possession of a concealed weapon5 and possession of a firearm by a former convict.6
The facts giving rise to this appeal are as follows. On May 28, 1975, appellant was convicted of first degree murder. On October 1, 1975, he was taken to the Philadelphia General Hospital and placed in a cell in the hospital’s prison ward. Later that day it was discovered that appellant had escaped through a window from which the bars had been cut. Appellant and two others solicited a ride from an individual named Dominick Stella, who deposited them at various locations throughout the city of Philadelphia. Stella *202noticed that when the three exited his automobile they left behind a hacksaw blade partially wrapped in tape. The next day he recognized appellant’s photograph in the newspaper and reported the incident to the police.
A few days later, a woman named Jacqueline Keim told a man named Carmen Sperduto that appellant was at her apartment. Sperduto saw a newspaper item detailing appellant’s escape and telephoned the police telling them that he had seen appellant and might know where appellant was. Based upon this tip, the police obtained an arrest warrant. On October 3, 1975, they forcibly entered Keim’s apartment and discovered appellant hiding in a bedroom under a child’s crib. In addition, they seized a revolver that was lying on top of a dresser, a few feet from the crib. After conviction, appellant brought the instant appeal alleging that the court below committed the following errors:
(1) the lower court erred in not granting his motion to suppress the revolver;
(2) the lower court erred in not sustaining his demurrer to the firearms charges because the Commonwealth failed to prove that appellant was in possession of the revolver found in the bedroom in which he was captured;
(3) his conviction under 18 Pa.C.S. § 907(a) should be reversed because a revolver does not constitute an instrument of crime;
(4) the Commonwealth failed to establish one of the elements of escape;
(5) the court erred in not permitting appellant to introduce evidence of the conditions at the Philadelphia prison as a defense to the charge of escape;
(6) the lower court erred in permitting the prosecution to introduce evidence regarding appellant’s prior conviction for first degree murder;
(7) the court erred in permitting the' prosecutor to amend the information to charge the offense under 18 Pa.C.S. § 6105.
For the reasons stated below, we affirm the judgment of the court below.
*203I-IV
The majority of this court embraces the analysis in the dissenting opinion regarding the first four assignments of error and, therefore, we will not expound upon those assignments.
V
Appellant’s fifth assignment of error is that the court below erred in excluding evidence regarding the conditions at the Philadelphia prison as a defense to the charge of escape. While agreeing with the lower court that the evidence was properly excluded, we wish to make clear our position on the use of duress as a defense to an escape charge.
Generally, Pennsylvania has refused to recognize a defense to a charge of escape based upon an illegality in one’s sentence or incarceration.7 The reason for this rule is obvious — the difficulties of prison administration would be intolerable if each prisoner was permitted to “go over the wall” as a means of testing the legality of his incarceration, rather than utilizing the customary means of administrative and judicial redress.8
The general prohibition against escape defenses is, however, not absolute. At common law, a defense of necessity was recognized for factors beyond the control of the prisoner.9 Moreover, the defense of duress was recognized *204as part of the common law of Pennsylvania, see Respublica v. M’Carty, 2 Dall. 86, 1 L.Ed. 300 (1781) (dicta), and has been incorporated as a statutory defense under the Crimes Code, 18 Pa.C.S. § 309. Therefore, the issue for determination is whether duress will be recognized as a defense to the crime of escape.
While of novel inquiry in Pennsylvania, courts in other jurisdictions have determined that the defense should be recognized, although they have disagreed at to what constitutes duress. The greatest source of disagreement has arisen with respect to whether the physical abuse of a prisoner by prison officials or other prisoners constitutes duress which justifies an escape,10 or whether such abuse merely relates to the “conditions” of imprisonment which should be remedied by a proper protest to prison or judicial officials.11 Although not directly presented in the instant case,12 we hold that such abuses are analogous to cases in which a prisoner is contesting the legality of his incarceration. Mere prison conditions, even those arising from physical abuse, will not constitute a defense to an escape charge; instead, a prisoner’s proper avenue of redress is through administrative or judicial channels. As one court stated:
“Since he was under lawful confinement, he had no legal right to resort to self-help as a method to assert his claim with respect to conditions in the prison.
*205The judicial system, as well as the prison administration, has long been recognized as the normal channels for meritorious complaints relating to prison conditions. [The defendant] could have registered his claimed grievances via these accepted avenues of redress.” State v. Dyer, 371 A.2d 1086, 1090-91 (Me.1977).
In reaching this conclusion, it must be recognized that the prison environment is wholly unlike that in the general population at large. A person in the general population, confronted by a situation compelling the commission of a crime, will in most cases have little or no opportunity to secure immediate aid from the proper authorities.13 In contrast, the prison environment, by definition, is replete with constant supervision by officials whose task is to ensure the safe operation of the prison system. Because of this constant and ready source of available aid, as well as the traditional remedies of habeas corpus, see Commonwealth ex rel. Bryant v. Hendrick, 444 Pa. 83, 280 A.2d 110 (1971); Commonwealth ex rel. Ford v. Jeffes, 260 Pa.Super. 432, 394 A.2d 1004 (1978), and actions under the federal Civil Rights Act (42 U.S.C. § 1983), see, e. g., Fox v. Sullivan, 539 F.2d 1065 (5th Cir. 1976); Campbell v. Beto, 460 F.2d 765 (5th Cir. 1972), for contesting oppressive prison conditions, we restrict the defense to all but the most extreme situations.
An example of such a situation was advanced in People v. Wester, 237 Cal.App.2d 232, 46 Cal.Rptr. 699 (1965), in which the court hypothesized that if a prisoner was confronted with a choice between accompanying an escaping cell mate, *206or being seriously injured if he chose to remain behind, then duress would be a defense. In such a case, the usual sources of aid would not be immediately available, and confronted with the choice between serious injury or escape, the defendant would properly be excused for choosing the latter course of action. Accord, State v. Alberigo, 109 Ariz. 294, 508 P.2d 1156 (1973); see Commonwealth v. Schwartz, 251 Pa.Super. 36, 379 A.2d 319 (1977) (by implication). Absent such an extreme situation, we refrain from opening the floodgates to permit Pennsylvania prisoners to raise the defense of duress to a charge of escape.
Finally, we emphasize the requirement outlined in the dissent’s summary of People v. Lovercamp, 43 Cal. App.3d 823, 118 Cal.Rptr. 110 (1974), that a defendant must return to official detention as expeditiously as possible after absenting himself from the danger that initially prompted his escape. Cf. United States v. Chapman, 455 F.2d 746 (5th Cir. 1972) (duress defense vitiated if defendant forced to escape by other prisoners but then remains at large on own volition).
VI
Appellant’s sixth assignment of error relates to the admission into evidence of his prior conviction for first degree murder. As stated, appellant had been found guilty of first degree murder on May 28, 1975, and was incarcerated at the time he escaped on October 1,1975. In addition to escape, appellant was charged under 18 Pa.C.S. § 6105, which prohibits a person from possessing a firearm if he has previously been convicted of a crime of violence. Under 18 Pa.C.S. § 6102 a crime of violence is defined as including
“[a]ny of the following crimes, or an attempt to commit any of the same, namely: murder, rape, aggravated assault, robbery, burglary, entering a building with intent to commit a crime therein, and kidnapping.” (emphasis added).
*207To support a conviction under 18 Pa.C.S. § 6105, it was incumbent upon the Commonwealth to prove beyond a reasonable doubt that appellant had been convicted of one of the crimes enumerated in 18 Pa.C.S. § 6102.14 See Commonwealth v. Todd, 477 Pa. 529, 384 A.2d 1215 (1978).
Cases are legion in which it is held that evidence is admissible if relevant to the matter under inquiry. E. g. Clark v. Essex Wire Corp., 361 Pa. 60, 63 A.2d 35 (1949). Evidence is deemed relevant if it tends to “prove or disprove the matters in issue.” Commonwealth v. Jones, 355 Pa. 594, 597, 50 A.2d 342, 344 (1947). Instantly, one of the “matters in issue” was whether appellant had been convicted of any crime detailed in 18 Pa.C.S. § 6102. Since the evidence was relevant to resolving this matter, we hold that it was properly admitted as an essential part of the Commonwealth’s case.15
While appellant concedes that it was necessary to inform the jury that he had been convicted of a crime of violence, *208he argues that it was prejudicial to inform them regarding the exact nature of the prior crime. As support for this proposition, appellant cites the the case of Commonwealth v. Scoggins, 466 Pa. 355, 353 A.2d 392 (1976).
In Scoggins, the defendant was charged, under The Penal Code,16 with first degree murder,17 and assault by a life prisoner.18 To prove that the defendant was incarcerated for a life term at the time he committed the assault, the prosecution introduced evidence that he had previously been convicted of first degree murder. In holding that the court erred in admitting the evidence, the supreme court emphasized that the exact nature of the prior crime was not a necessary element of proof in establishing that the defendant was serving a term of life imprisonment.19 In contrast, the crime charged in the instant case required the introduction into evidence of the exact nature of the prior crime. While in Scoggins the question whether the defendant was serving a life sentence could easily be determined without reference to the prior crime, the instant case required proof *209of the prior crime for the jury to determine whether it was or was not a crime of violence.20
Moreover, the instant case is distinguishable from Scoggins in one material respect. In Scoggins, the defendant was being tried for first degree murder and the evidence that was presented established that he had previously been convicted for the same offense. Because the general prohibition against the introduction into evidence of prior crimes is to prevent the jury from concluding that the accused has a propensity for criminal activity by reason of his prior conviction, see, e. g., Commonwealth v. Allen, 448 Pa. 177, 292 A.2d 373 (1972); Commonwealth v. Trowery, 211 Pa.Super. 171, 235 A.2d 171 (1967), this fear is particularly acute when the jury is informed that the defendant’s prior crime was the same as one of the crimes for which he is currently being tried. In contrast to Scoggins, the instant charges against appellant did not encompass the same crime for which he had previously been convicted. Therefore, the feared prejudice regarding the jury’s belief in appellant’s propensity for certain criminal activity was not as great as in Scoggins. This, coupled with the fact that the jury was not informed as to the facts of the prior crime, plus the judge’s instruction regarding the limited use of the evidence, was sufficient to vitiate any prejudice.
Finally, although no cases have been decided under 18 Pa.C.S. § 6105 or its historic antecedent under The Penal Code, (see Act of June 24, 1939, P.L. 872, § 628, as amended, 18 P.S. § 4628(d)) cases from other jurisdictions have held *210that the exact nature of the prior crime may be introduced as a proper element of proof under statutes similar to that in Pennsylvania.21 In addition, numerous jurisdictions have statutes prohibiting a former convict from possessing a firearm if the prior crime was a felony, but without the specific Pennsylvania requirement that the prior crime be one of violence. Even in those jurisdictions, evidence of the exact nature of the prior crime has been held admissible as establishing an essential element of the pending offense.22 Indeed, cases have been reversed when the prosecution failed to establish that the prior crime was one of violence23 or was a felony,24 when those factors were essential elements in the proof of the subsequent crime of possession of a firearm.
Therefore, we rule that the evidence was admissible as an essential part of the Commonwealth’s proof of 18 Pa.C.S. § 6105.
*211VII
Finally, we are confronted with appellant’s contention that the court below erred in permitting the prosecution to amend the information to allege a violation of 18 Pa.C.S. § 6105, “[f]ormer convict not to own a firearm.” Appellant had initially been charged with possession of a firearm by a former convict (18 Pa.C.S. § 6105), and carrying a firearm without a license (18 Pa.C.S. § 6106). At a trial in the Philadelphia Municipal Court, appellant was found guilty under 18 Pa.C.S. § 6105, while the charge under 18 Pa.C.S. § 6106 had been dismissed earlier. Appellant then appealed for a trial de novo in the Philadelphia Court of Common Pleas. In drawing the information, the prosecutor inadvertently charged appellant with violating 18 Pa.C.S. § 6106 and § 6108 (carrying a firearm in public): During pre-trial motions, the Commonwealth moved to amend the information to delete the charges under § 6106 and § 6108 and to substitute the offense for which appellant had been convicted in the municipal court, § 6105. Appellant contends that this substitution was impermissible under Pa.R.Crim.P. 229. We disagree.
Pa.R.Crim.P. 229 provides that an information may be amended if
“there is a defect in form, the description of the offense, the description of any person or any property, or the date charged, provided the information as amended does not charge an additional or different offense.” (emphasis added).
See also Act of March 31, 1860, P.L. 427, §§ 12, 13, 19 P.S. §§ 432, 433. Appellant alleges that the deletion of the charges under 18 Pa.C.S. § 6106 and § 6108 and the substitution of the charge under 18 Pa.C.S. § 6105 entails the charging of an “additional or different offense.” While appellant’s contention is supported by a superficial reading of Rule 229, it is unsubstantiated by the Pennsylvania precedents interpreting that provision.
*212The purpose of Rule 22925 is to insure that a defendant is fully appraised of the charges against him, and to avoid prejudice by prohibiting the last minute addition of alleged criminal acts of which the defendant is uninformed. See Commonwealth v. Jones, 250 Pa.Super. 471, 378 A.2d 1245 (1977); Commonwealth v. King, 227 Pa.Super. 168, 323 A.2d 260 (1974). In effecting this purpose, the courts of this Commonwealth employ the test of whether the crimes specified in the original indictment or information involve the same basic elements and evolved out of the same factual situation as the crimes specified in the amended indictment or information. If so, then the defendant is deemed to have been placed on notice regarding his alleged criminal conduct.26 If, however, the amended provision alleges a different set of events,27 or the elements or defenses to the amended crime are materially different from the elements or defenses to the crime originally charged, such that the *213defendant would be prejudiced by the change,28 then the amendment is not permitted.
Instantly, appellant was informed at the municipal court level of both the charge and the events giving rise to the offense of possession of a firearm by a former convict, 18 Pa.C.S. § 6105. His defense at that time, and at the trial de novo in the court of common pleas, was that he was not in possession of the weapon found on the dresser, since mere proximity to the weapon was insufficient to establish possession, and the weapon may have belonged to others who had equal access to the bedroom. At no time did appellant challenge his status as a former convict, the only additional element in the amended offense that was not encompassed in the offenses originally charged. Moreover, the facts alleged in the information charging appellant with the offenses under 18 Pa.C.S. § 6106 and § 6108 were not changed when those charges were deleted and 18 Pa.C.S. § 6105 was substituted in their stead. Accordingly, because appellant was fully appraised of the charges and the events concerning § 6105 at the municipal court,29 and because his defense was unaffected by whatever “label” was attached to those events, we can perceive of no prejudice to appellant by permitting the amendment.
Judgment of sentence affirmed.
SPAETH, J. files a dissenting opinion. JACOBS and WATKINS, former President Judges, and HOFFMAN, J., did not participate in the consideration or decision of this case.. 18 Pa.C.S. § 5121.
. 18 Pa.C.S. § 5122.
. 18 Pa.C.S. § 907(a).
. 18 Pa.C.S. § 908.
. 18 Pa.C.S. § 907(b).
. 18 Pa.C.S. § 6105.
. See 18 Pa.C.S. § 5121(c); Commonwealth v. Storm, 185 Pa.Super. 136, 138 A.2d 140 (1958); Commonwealth ex rel. Penland v. Ashe, 142 Pa.Super. 403, 17 A.2d 224 (1941); Commonwealth v. Francies, 73 Pa.Super. 285 (1919).
. This court has also held that neither the negligence of prison officials in permitting an escape, nor the necessity of a prisoner to attend to certain family matters will suffice as a defense to an escape charge. See Commonwealth v. Longenberger, 261 Pa.Super. 472, 395 A.2d 1006 (1978); Commonwealth v. Schwartz, 251 Pa.Super. 36, 379 A.2d 319 (1977).
. “If the prison be fired by accident, and there be a necessity to break prison to save his life, this excuseth the felony . . .” 1 Hale, History of the Pleas of the Crown, 611 (1680).
. People v. Lovercamp, 43 Cal.App.3d 823, 118 Cal.Rptr. 110 (1974); People v. Unger, 66 Ill.2d 333, 5 Ill.Dec. 848, 362 N.E.2d 319 (1977); State v. Boleyn, 328 So.2d 95 (La.1976) (by implication); People v. Luther, 394 Mich. 619, 232 N.W.2d 184 (1975); People v. Harmon, 53 Mich.App. 482, 220 N.W.2d 212 (1974), affd., 394 Mich. 625, 232 N.W.2d 187 (1975).
. State v. Alberigo, 109 Ariz. 294, 508 P.2d 1156 (1973); State v. Dyer, 371 A.2d 1086 (Me. 1977); State v. Green, 470 S.W.2d 565 (Mo.), cert. denied, 405 U.S. 1073, 92 S.Ct. 1491, 31 L.Ed.2d 806 (1971).
. Appellant’s proffered evidence did not entail allegations of physical abuse, but instead, related to actual conditions of imprisonment, i. e., overcrowding and lack of medical care.
. See State v. Ragland, 4 Conn.Cir. 424, 233 A.2d 698 (1967); State v. Miller, 187 So.2d 461 (La.App.1966); City of Hamilton v. Collier, 44 Ohio App.2d 419, 339 N.E.2d 851 (1975) (duress when defendant under arrest or detention and acted pursuant to orders of police); cf. State v. Kearns, 27 N.C.App. 354, 219 S.E.2d 228 (1975) (no duress when defendant had opportunity to escape); LaBryer v. State, 45 Ala.App. 33, 222 So.2d 361, cert. denied, 284 Ala. 732, 222 So.2d 366 (Ala. 1969) (no duress when accomplice engaged in sodomy on two different occasions and had opportunity to report to police in interim). But cf. State v. Toscano, 74 N.J. 421, 378 A.2d 755 (1977) (duress defense available even though defendant had opportunity to report to police but did not out of fear police would be ineffective in affording protection).
. Appellant offered to stipulate that the crime for which he had previously been convicted was a crime of violence. However, in Commonwealth v. Evans, 465 Pa. 12, 348 A.2d 92 (1975), the supreme court ruled that the Commonwealth was not bound to accept proffered stipulations.
“The general rule is that a party to an adversary court litigation may prove his case by proper evidence and may not be required to accept, in lieu of such evidence, a stipulation as to what it would prove. . . . The Commonwealth has the burden of proving the guilt of the defendant beyond a reasonable doubt; it must be permitted to do that by whatever material it can muster.” Id., 465 Pa. at 17, 348 A.2d at 94-95.
Moreover, courts in other jurisdictions have held that the prosecution need not accept similar stipulations when defendants are being tried under analogous statutes. See United States v. Smith, 520 F.2d 544 (8th Cir. 1975); State v. Taylor, 31 Or.App. 135, 571 P.2d 508 (1977).
. In its brief, the Commonwealth poses an alternative argument and states that the evidence was also admissible to prove that appellant was under “official detention,” a necessary element in the crime of escape. We find this argument to be without merit since the jury was not required to know the exact nature of the prior crime in order to conclude that appellant was under “official detention” at the time he escaped from the Philadelphia General Hospital. Cf. Commonwealth v. Markle, 245 Pa.Super. 108, 369 A.2d 317 (1976) (informing jury that prior crime was felony was permissible, but not exact nature or details of crime).
. Act of June 24, 1939, P.L. 872, §§ 101 et seq., 18 P.S. §§ 4101 et seq., repealed, Act of Dec. 6, 1972, P.L. 1482, § 5.
. Id. at § 701, as amended, 18 P.S. § 4701.
. Id. at 710.2, as amended, 18 P.S. § 4710.2.
. The court went on to conclude that the admission of the exact nature of the prior crime was not prejudicial in as much as the jury would conclude that the prior crime was of “the most egregious sort” simply by being informed that the defendant had been sentenced to life imprisonment. In light of this necessary prejudice, no additional prejudice resulted from informing the jury that the prior crime had been first degree murder, and the evidence was merely cumulative. Commonwealth v. Scoggins, supra, 466 Pa. at 361, 353 A.2d at 395.
Although not raised by appellant, we note that a similar result would pertain to the instant case with respect to informing the jury as to the exact grade of appellant’s prior murder conviction. To satisfy the requirements of 18 Pa.C.S. § 6102 the jury need only be informed that appellant had previously been convicted of murder generally. In light of this prejudice, we can perceive of no additional prejudice accruing to appellant by informing the jury regarding the exact degree of the prior murder conviction. Commonwealth v. Scoggins, supra.
. The need to detail to the jury the nature of the prior crime is perhaps underscored by the fact that appellant was acquitted of the charge of possession of a firearm by a former convict, 18 Pa.C.S. § 6105. Since the events charged for that offense were the same as the events for possession of an instrument of crime, 18 Pa.C.S. § 907(a), and possession of a prohibited offensive weapon, 18 Pa.C.S. § 908, with the additional element that appellant had previously been convicted of a crime of violence, it is incongruous that the jury acquitted appellant of the former charge but convicted him of the latter two charges. Either the jury chose to return an inconsistent verdict, see Commonwealth v. Parrotto, 189 Pa.Super. 415, 150 A.2d 396 (1959), or the prosecution failed in its proof of an essential element of 18 Pa.C.S. § 6105.
. See English v. State, 295 Ala. 98, 323 So.2d 728 (1975) (by implication); Bell v. State, 47 Ala.App. 516, 257 So.2d 375 (1972); State v. Robinson, Del., 251 A.2d 552 (1969); Powell v. State, 538 S.W.2d 617 (Tex.Crim.App.), cert. denied, 429 U.S. 928, 97 S.Ct. 334, 50 L.Ed.2d 298 (1976).
. United States v. Smith, 520 F.2d 544 (8th Cir. 1975), cert. denied, 429 U.S. 925, 97 S.Ct. 328, 50 L.Ed.2d 294 (1976); United States v. Boyer, 421 F.2d 842 (9th Cir. 1970); United States v. Mason, 68 F.R.D. 619 (D.Md.1975); People v. Jackson, 53 Cal.2d 89, 346 P.2d 389 (1959); People v. Faulkner, 28 Cal.App.3d 384, 104 Cal.Rptr. 625 (1972); People v. Willis, 43 Ill.App.3d 535, 2 Ill.Dec. 409, 357 N.E.2d 576 (1976); People v. Perry, 35 Ill.App.3d 50, 340 N.E.2d 585 (1975); People v. Lampkins, 28 Ill.App.3d 246, 328 N.E.2d 100 (1975); State v. Hoover, 219 Or. 288, 347 P.2d 69 (1959); State v. Taylor, 31 Or.App. 135, 571 P.2d 508 (1977).
. See Mendoza v. State, 460 S.W.2d 145 (Tex.Crim.App.1970); Waffer v. State, 460 S.W.2d 147 (Tex.Cr.App.1970) (Texas statute did not define crime of violence); cf. Powell v. State, supra (adequate proof presented). See also State v. Robinson, supra (indictment defective when merely alleges prior crime was one of violence without specifying exact nature of the crime of violence).
. Cf. People v. Lampkins, supra (adequate proof presented). See also Watson v. State, 291 So.2d 741 (Miss.1974) (conviction reversed when indictment merely alleged prior crime was a felony without specifying the exact nature of the felony).
. While the cases discussed infra are interpretive of Pa.R.Crim.P. 220, they may be utilized in determining the extent of Rule 229. The provisions of the two rules are identical, and differ only in that Rule 220 is applicable to indictments while Rule 229 applies to informations.
. Cf. Commonwealth v. Boone, 450 Pa. 357, 301 A.2d 699 (1973) (charge of murder amended to include voluntary manslaughter, a lesser included offense); Commonwealth v. Fowler, 259 Pa.Super. 314, 393 A.2d 844 (1978) (charge of conspiracy to commit robbery and theft amended to include conspiracy to commit aggravated assault); Commonwealth v. Coles, 226 Pa.Super. 488, 313 A.2d 329 (1974) (charge of larceny of automobile amended to include larceny of tape recorder and tapes in the auto).
. Cf. Commonwealth v. Swint, 465 Pa. 450, 350 A.2d 851 (1976) (charge of possession of firearm at time of arrest different from original charge of possession at time of murder when the arrest occurred twenty-nine days after the original murder). But cf. Commonwealth v. King, 227 Pa.Super. 168, 323 A.2d 260 (1974) (amendment to charge drug sale at 1:00 p. m. permissible even though evidence at preliminary hearing informed defendant he would have to defend against an alleged sale at 3:00 p. m. or 7:00 p. m. of the same day).
. Commonwealth v. Bruce, 230 Pa.Super. 507, 326 A.2d 628 (1974) (amendment to allege burglary with intent to commit murder different from burglary with intent to commit larceny since elements of offenses and defenses are different).
. In Commonwealth v. Nelson, 230 Pa.Super. 89, 326 A.2d 598 (1974), we held that the municipal court proceedings serve to apprise a defendant of the nature of the charges, and in that respect, obviate the need to conduct a preliminary hearing on those charges.