Thieves who broke into four Brooklyn Park schools spent hours in the buildings searching for iPads, then turning them on trying to figure out which ones were worth stealing, authorities said Tuesday.

In the end, it wasn’t many.

That’s because Osseo Area Schools had thought ahead to just this type of scenario when it set out to place an iPad in nearly every student’s hands.

The district owns 15,000 iPads. The newer ones are part of Apple’s Device Enrollment Program, which means they’re exclusive to the school district. Enrolled devices are password-protected and cannot be restored to factory settings and resold.

“The new ones were worthless to [the thieves], so it was the old ones they needed, because they could be freed up,” said Brooklyn Park Deputy Chief Mark Bruley.

Two men have been arrested in the burglaries, and police are searching for a third suspect. Charges are pending.

The burglars broke into SAGE Academy and Crest View Elementary School early Friday after hitting Palmer Lake Elementary and Birch Grove Elementary a few days before, authorities say.

The heists took place between midnight and 4 a.m. The thieves spent hours searching for iPads, laptops and other small electronics. Much of their activity was captured on school surveillance cameras.

“They were all over in different classrooms,” Bruley said. “They were going through the entire building looking. … We’ve gathered some good evidence from the crime scene. We pulled fingerprints and DNA.”

The Hennepin County crime lab processed the crime scenes. Police also found evidence linking the suspects to the thefts at a Brooklyn Park home.

Bruley said the district’s security measures helped minimize the amount stolen and nab the thieves.

School officials turned over video footage to police, and a detective used Facebook to identify the three men in the footage.

Barbara Olson, spokeswoman for the Osseo district, said the losses were small. “There was no loss at one of the buildings and the losses at the two others were a handful of iPads and miscellaneous other small items,” she wrote in an e-mail. “We anticipate that the total losses won’t be sufficient to reach our insurance deductible.”

Osseo is the fifth-largest school district in the state, serving more than 20,000 students in parts of Brooklyn Center, Brooklyn Park, Corcoran, Dayton, Maple Grove, Osseo, Plymouth, and Rogers.