While they were investigating, the marked police car was taken.
Officers found the abandoned police cruiser a little more than an hour later about 10 miles away in La Puente, but the guns were gone.
The guns that are missing are an AR-15 semiautomatic assault rifle and a 12-gauge Remington shotgun.
Montebello police say the car was not damaged and only the loaded weapons were missing. They say they're very concerned about the public's safety and want to find the weapons and the suspect.
The department is investigating whether the keys were left in the patrol car when officers got out of the vehicle.
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