Under state law, red-light cameras can only be used to catch traffic infractions.
King County Prosecutor Dan Satterberg, however, is pushing to change that law.
"I think it's ridiculous to say you can use the evidence for that infraction, but you can't use it to solve a murder," Satterberg said to KIRO 7 Eyewitness News reporter John Knicely.
Satterberg pointed to the unsolved Nicole Westbrook murder. The 21-year-old was killed in April in a drive-by shooting in Pioneer Square.
Surveillance video from a nearby business barely shows the car and suspect, but no license plate.
The shooter's vehicle was headed right toward a red-light camera. Prosecutors are convinced that if they could have used footage from the camera and from those at other intersections, they could have caught Westbrook's killers right away, possibly that night.
"We suspect that car probably ran the red light in the intersection, but we'll never know and we're prohibited by law from even looking," Satterberg said.
Douglas Honig of the ACLU said that he believes using red-light cameras beyond traffic violations will violate people's rights.
"They shouldn't be used to track people's movements," Honig said. "When they were set up it was with a guarantee, because of public concern about privacy, that it would just be used for traffic enforcement, and those rules shouldn't be changed."
Satterberg, however, said that people on a public street should have no expectation of privacy.
"We should be able to go to a judge and ask for a search warrant when a crime has been committed in that intersection," he said.
Satterberg's proposed bill will be introduced in the House Transportation Committee on Wednesday. It has the backing of many police agencies.