Evidence in more than 500 cases, many of them murders and rapes, was contaminated after power was accidentally cut off in a crime lab's freezer, officials said Friday.
A cleaning crew tripped a circuit breaker Dec. 10, causing hundreds of frozen samples of blood and other body fluids to defrost, Deputy Police Chief Bob Busby said.The Tulsa Police Department's laboratory freezer remained off until Monday morning. Evidence was contaminated in 543 cases, 52 of them murders.
"This is truly the lifeblood for some of the cases we have in court," Police Chief Ron Palmer said.
"We know that we have some samples that are irreplaceable that have been destroyed," he said.
District Attorney David Moss said he was awaiting more information from police before determining the magnitude of the accident on pending cases.
"I'm not going to be an alarmist until I see cases that were affected," he said.
Samples in 306 cases probably have been destroyed, Busby said. Evidence in the other 237 cases was contaminated, but investigators should be able to obtain more samples from the victims and suspects, he said.
Blood swabs and other samples were contaminated when they dissolved in the water. The freezer is the only one in the lab.
Many of the samples involve rape and murder cases, some of which may have already been adjudicated, Palmer said.
The department is investigating why the freezer wasn't checked after an alarm warned it had lost power.