A man who was allegedly waving a BB gun outside a Portland shopping plaza was shot and killed by police Saturday.

The Portland Press Herald reports the incident happened shortly after 11:00 Saturday morning outside the Union Station Plaza, a strip mall on St. John Street. Police say the man went into the Coastal Trading and Pawn shop and bought a BB gun. He then walked outside and started pointing it around the parking lot and at the sky.

Police were called in and tried to get the man to drop the gun. Witnesses say the man put the gun down in order to pull up his pants. Officers told him not to pick up the weapon again and, when he did, he was shot him in the head by police.

The parking lot was cordoned off and, for some shoppers, it was as much as a four hour wait before they were able to move their cars. The incident remains under investigation, which is standard procedure in a police-involved shooting. So far, the man's name has not been released by police.