It's being called the Drew Peterson Law.
The Illinois General Assembly on Wednesday approved a bill that could have a big impact on Peterson if he's ever charged in the disappearance of his wife, Stacy.
The new state law allows hearsay to be admitted as evidence in cases where prosecutors believe the victim was killed specifically to prevent them from testifying.
Will County State's Attorney James Glasgow pushed for the law and said it wasn't designed to target Drew Peterson or any specific individual, but he said he intends to use it.
"I expect to use this law aggressively in any case where it applies," Glasgow said.
The law might also come into play in the Savio case. She sent a letter to a prosecutor that said, Peterson "knows how to manipulate the system, and his next step is to take my children away. Or kill me instead."
Peterson's attorney, Joel Brodsky, said he believes it's unlikely the law would affect his client.
Because the Senate last week approved changes to the bill made by Gov. Rod Blagojevich, the House action allows the legislation to take effect immediately.