Multiple photos posted on the Irvine Police Department's Instagram and Facebook show the same man tampering with critical devices meant to prevent wildfires.
Police say this has been happening in the open space area near Lake Forest and Bake Parkway.
"These devices are critical to keeping our community safe," said police in a statement.
It's unclear when these incidents took place, but officers are asking the public's help to identify the man. In one photo, the man is seen wearing cargo shorts and a white T-shirt. In another, he's seen riding a black bicycle.
Anyone with information is urged to contact the Irvine Police Department.