Pennsylvania gives prosecutors and the government extreme powers and tools to prosecute sex assault, child abuse, and domestic violence claims. Defendants need to be careful when addressing sex assault allegations – the government has an extreme amount of power not afforded for other subject matters.

Jury Instructions

In the jury instructions, judges are forbidden from providing any additional instructions just because the nature of the allegation (a sex offense) is tricky and emotionally difficult to process. It is common in jury trials for the prosecutor to mention that, in sex assault cases, only one witness (if believed by the jury) is needed to prove a defendant guilty of a sex crime beyond a reasonable doubt.

Just recently in 2024, Pennsylvania amended jury instructions to give even more deference to prosecutors:

• Standard instruction 4.13A was removed, which instructed the jury to consider whether the complaint of sex assault was "prompt"
• Standard instruction 4.13B was added, which essentially parrots a Commonwealth talking point that a jury can convict someone even if the testimony of the complaining witness is completely uncorroborated

Special Hearsay Exceptions

Prosecutors are also given special powers to use hearsay evidence in sex assault cases – using the "prompt complaint" witness or the "tender years" exception.

Section 5920 Expert Witnesses

Yet another tool is Section 5920, which allows for specialized expert testimony in a sex assault trial. This section allows an expert witness who can "assist the trier of fact in understanding the dynamics of sexual violence… victim responses to sexual violence… and the impact of sexual violence or domestic violence during and after being assaulted."

The section can cause tremendous problems in a criminal case and for a criminal defendant:

1. The study of behaviors and psychology aren't exact sciences
2. The potential testimony is also what I like to call "shadow bolstering" or supporting another witnesses' testimony without directly calling them credible or believable
3. The expert testimony is potentially conclusory and inconsistent with controlled observations — if an alleged complaining witness remains silent, that could be "evidence" of being a victim; if the alleged complaining witness speaks out, that is also "evidence" of being a victim

The Rape Shield Act

The Rape Shield Act generally forbids defense litigants from bringing up any sexual proclivities or previous conduct of the complaining witness – the goal being to prevent hypothetical defense "smearing" of a complaining witness.