A gun was stolen from an unmarked police vehicle parked outside an officer’s home in San Jose, police said.

The department said someone broke into the car and stole the firearm.

The department declined to identify the officer, but the assistant chief confirmed to NBC Bay Area that is was his vehicle and firearm. He said the gun was in a lockbox, which had been broken into.

“If it’s a vehicle, it has to be out of sight, it has to be in a locked container that is permanently affixed to the vehicle with a substantial lock,” public safety consultant and retired San Jose police detective Michael Leininger said. “The fact that this was stolen, I question how substantial it was. If it was substantial, I don’t think they should have been able to remove it.”

No arrests had been made as of Tuesday.