Prosecutors said three murder cases in King County are being affected because there's evidence from red light cameras that they cannot use.

Investigators want footage from traffic safety cameras that may show the killers, and to use it, they need to get a state law changed.

In Olympia on Wednesday, lawmakers will hold a hearing on that proposal.

 Nicole Westbrook, 21, was shot and killed nearly a year ago in Pioneer Square in a drive-by shooting.  Her slaying remains unsolved.

Police believe the killer ran a red light after the shooting.

If so, there would be surveillance video of the side of the car and its license plate.

But state law prohibits the use of traffic camera footage for any purpose other than to prove a traffic violation.

House Bill 1047 would change that law and allow police agencies to use photos and video from traffic cameras, including red light and toll booth cameras.

The ACLU opposes changing the law because it says using traffic footage for criminal or other purposes violates civil rights.

The House Safety Committee will hold a hearing on the bill Wednesday afternoon.