Opinion by
Watkins, P.J.,This is an appeal from the judgment of sentence of the Court of Common Pleas of Montgomery County, Criminal Division, by the defendant-appellant after conviction by a jury of theft by receiving stolen property, criminal conspiracy, possession of instruments of crime with intent, possession of weapon with intent, possession of offensive weapon, violation of the Uniform Firearms Act, escape, resisting arrest, false report to law enforcement authorities and unauthorized use of a motor vehicle; and from the denial of post trial motions.
The defendant was arrested on June 16, 1974 when police officers stopped a 1963 Ford van for a loud exhaust and improper muffler and saw in plain view inside the van an unlawful firearm. A search of the van revealed burglary tools, weapons, ammunition and stolen goods. After being taken to the police station the defendant escaped from his cell but was later apprehended by the police.
The defendant alleges several grounds in support of reversal. First, he contends that the court below erred when it refused defendant’s point for charge to the jury that mere presence is not sufficient evidence to support a conviction for possession of firearms or receiving stolen goods. However, it is not error for a court to refuse to charge the jury on matters that it has already covered in its charge. Commonwealth v. Jones, 452 Pa. 569, 308 A.2d 598 (1973). A review of the court’s charge to the jury reveals that the court below adequately charged the jury with regard to these crimes, explaining several times the elements which were necessary to be proven before a conviction could be returned against the defendant. Therefore this contention of the defendant is not a reason for reversal of his convictions.
The defendant also contends that the court below erred when it allowed defendant’s prior criminal record to be introduced against him when he took the witness stand in his own defense. In the case of Commonwealth v. *216Bighum, 452 Pa. 554, 307 A.2d 255 (1973), the court recognized that serious problems arise when a defendant’s prior criminal record is used to impeach his testimony at trial since this may have a dampening effect on his right to testify in his own behalf. In Bighum, supra, the court established a balancing test to apply to such situations. The court below must balance the importance of the jury’s hearing the defendant’s story against the importance of its being informed of his prior convictions. Several other factors to be considered in weighing the question are the age and nature of the prior crime, the length of the criminal record, and the age and circumstances of the defendant. The ultimate question of whether to allow such evidence lies within the sound discretion of the trial judge after weighing these various factors.
In the instant case the record reveals that the evidence of the defendant’s prior crimes included conviction of burglary, larceny, and receiving stolen property on June 7, 1973. Since these crimes are ones involving moral turpitude and do reflect dishonesty on the part of the defendant and since the defendant’s conviction of such offenses took place a relatively short time prior to his trial on the instant charges, we hold that, taking into account the entire situation, the court below did not abuse its discretion in admitting evidence of the prior convictions for the purpose of impeaching the defendant’s credibility. In its search for truth the jury was certainly entitled to consider the defendant’s testimony in light of his prior criminal conduct. See, Commonwealth v. Kahley, Pa. , 356 A.2d 745 (1976).
The defendant’s third contention is that the trial court erred when it sustained the Commonwealth’s objection to an aspect of the defendant’s cross-examination of Officer Januzelli, a Commonwealth witness. The defendant attempted to cross-examine Officer Januzelli as to allegedly false statements he had *217made in an unrelated case. The court sustained an objection to this line of questioning on the grounds that the proper way to attack a witness’s credibility is through witnesses called to the stand to testify as to his bad reputation for truth or veracity in the community. The case of Commonwealth v. Hansell, 185 Pa. Superior Ct. 443, 137 A.2d 816 (1958), clearly held that the proper manner by which to impeach a witness is through evidence indicating a bad reputation for truth and veracity in the neighborhood in which he resides and not through evidence of particular acts. In Commonwealth v. Donnelly, 233 Pa. Superior Ct. 396, 417, 336 A.2d 632 (1975), we held that “the scope of cross-examination is largely within the sound discretion of the trial judge, and even if a ruling is erroneous, the error is not grounds for reversal unless it results in apparent injury.” In the instant case we hold that the trial court did not abuse its discretion in limiting the type of cross-examination directed at Officer Januzelli.
Finally, the defendant contends that the charges against him should have been discharged with prejudice since he was not tried until April 21, 1975 in violation of the “270-day rule” then in effect. Pa. R. Crim. P. 1100 provides that defendants against whom a written complaint is filed after June 30, 1973 but before July 1, 1974 were to be tried no later than 270 days from the date the complaint was filed. The defendant was charged on June 16, 1974. Therefore the “270-day rule” applies to him. Since the defendant’s trial did not commence until April 21, 1975, it is apparent that he was not tried within 270 days of his arrest. However, Rule 1100(c) provides for a procedure by which the Commonwealth may apply to the court for an extension of time in which to try the defendant. The court may extend the time, in its discretion, as long as the Commonwealth has exercised due diligence in its attempts to bring the defendant to trial.
On March 12, 1975, the 269th day after the original *218complaint, the Commonwealth filed a petition to extend the time. On April 21, 1975, prior to the beginning of the trial, an on-the-record argument as to the petition to extend was held before the trial court. This hearing revealed that the case had been listed for trial on November 18, 1974, on December 14, 1974, on January 27, 1975 and on March 3, 1975. It was not reached on any of those occasions. The November 18, 1974 continuance was granted because the defense counsel was arguing before the Supreme Court. See Pa. R. Crim. P. 1100. On the other dates the case was not reached because they fell on days near the end of the criminal term of court and the court felt that since this case would require several days to try, the case could not be completed by the end of the criminal term. There was no showing that the District Attorney’s Office was responsible for the delays.
The dissenting opinion in this case would hold that the courts and the court administrator as well as the district attorney’s office be included within the term “Commonwealth” and that the district attorney’s office be held responsible for any delays occasioned by “lack of due diligence” on the part of the courts. However, we feel that the courts are not the instruments of the district attorney’s office nor the prosecution but are impartial tribunals established to mediate disputes between the “Commonwealth” and individuals. As such they are open to everyone but are not the agents of either the prosecution or the defense. Thus we feel that the prosecution or “Commonwealth” should not be prejudiced in its case when it has proceeded with due diligence in processing the.case. Furthermore we find no abuse of discretion on the part of the trial court in granting the extension of time when the prosecutor has filed a timely request for such extension and the defendant has had an opportunity to argue his position in favor of dismissal pursuant to Rule 1100. This is especially so where the defendant’s trial commenced within 39 days after the original 270-day period. The purpose of Rule 1100 is to *219prevent unconscionable delays in bringing a defendant to answer charges against him. Under the circumstances of this case we find that defendant’s right to a speedy trial was amply protected. Therefore we refuse to dismiss the charges against the defendant pursuant to Rule 1100.
Judgment of sentence affirmed.
Hoffman, J., took no part in the consideration or decision of this case.