In criminal trials in Philadelphia, one pretty common defense tactic is pointing the finger at another person at trial. This can raise enough doubt to result in a not guilty verdict by the judge or jury that the defendant was not the perpetrator of the crime.

Here’s an example: Two residents of Philadelphia, Mr. A and Mr. B, are riding in the backseat of a car which is pulled over for speeding. On the floor of the backseat is a bag of cocaine, which the officer sees in plain view when he walks up to the driver’s side door. When he asks who owns the bag of drugs, no one answers. He arrests everyone in the car for possession of a controlled substance. At Mr. A’s trial, he can present evidence that the drugs were in fact, owned by Mr. B. Not only can Mr. A testify that he knew about or touched the drugs, he may be able to introduce evidence that Mr. B has previously been convicted of possession of cocaine.

If you’re facing criminal charges, please contact our Philadelphia criminal law firm for a FREE consultation. Firm founder David S. Nenner fights tooth and nail for his clients and is recognized as a TOP RATED CRIMINAL DEFENSE ATTORNEY IN PHILADELPHIA by Super Lawyers.

Call (215) 564-0644. Cases are accepted throughout the southeastern Pennsylvania region including Philadelphia, Lehigh Valley, etc.


Historically, in Pennsylvania criminal cases, trial courts have applied a stringent 2 part test when admitting evidence of another person’s crimes or acts:

  1. The time prong which looks at the time lapse between the commission of the 2 acts or crimes.
  2. The signature prong, which looks at the resemblance between the two; there must be sufficient similarity between the two crimes or acts.

Recently, the Pennsylvania Supreme Court reviewed and rejected the 2 prong test. Instead, criminal defendants only have to show relevance under PA Rule of Evidence 401:

Evidence is relevant if: (a) it has any tendency to make a fact more or less probable than it would be without the evidence; and (b) the fact is of consequence in determining the action.

See Commonwealth v. Yale (April 29, 2021).

Under the simplified standard for admitting evidence, trial courts will still look the time between the two acts and whether the acts were similar, in addition to any other factor. This means that whether a criminal defendant will be allowed to introduce evidence of another person’s guilt will vary from case to case. Here’s an example.


A Philadelphia man (A) is charged with manufacturing meth after police execute a search warrant for his friend (B). The warrant is executed at A’s house. Police find B hiding in A’s bedroom closet. In A’s bedroom police find evidence of meth manufacturing including batteries, chemicals and soda bottles. Both A and B are charged with manufacturing meth. At A’s trial, he wants to admit evidence that the B was the one who was making meth.

Let’s take a look at relevance in this scenario by analyzing different facts to see whether a court would allow the evidence.

  1. B has a prior record for marijuana possession. Regardless of when B’s prior convictions occurred, a trial court is unlikely to allow evidence that B was previously convicted of possessing marijuana because there’s no similarity whatsoever.
  2. B had previously been convicted of meth possession (not manufacture) 2 years prior to the arrest. This too, has remote relevance because possession is clearly not manufacture.
  3. B had previously been convicted of making meth using the same materials 5 years prior to the arrest. The fact that B was previously convicted of making meth using the same materials is clearly relevant. However, the time lag of 5 years between the 2 acts makes this a close call. A trial court could go either way.