"We believe the suspect was going to sell them to a fence, a person who deals with stolen property, and he probably would have gotten $400 or $500 each without any questions asked," said Jim Amormino of the Orange County Sheriff's Department.
It will cost victims about $2,000 to replace each one.
Officials say the device needed to properly run fire-sprinkler systems are valuable for the copper and brass. Investigators say these thefts are on the rise.
Authorities say hundreds of these devices have been stolen across Orange County over the past year. In this case, the suspect was able to remove them in about two minutes each.
The 39-year-old Foothill Ranch resident was stopped by a deputy on patrol around midnight. Authorities allege Johnson told them he was an inspector, but a deputy noticed his license plate was covered up. He also had a stolen plate in the back.
Authorities suspect Johnson may be connected with other thefts, including more than 30 in Lake Forest earlier this month.
"These things are not commonly checked and the victims may not even know they've been stolen," Amormino said.
Johnson is facing grand theft and possession of stolen property charges.
Investigators are trying to determine if others were helping him. If you have any information, call the O.C. Sheriff's Department at (714) 628-7170.