9:00 P.M. UPDATE: Around 4:30 p.m. Sunday afternoon, Maryville Police Chief Tony Crisp told 10News a family member called 9-1-1, worried about a man who wandered off and appeared to be suicidal.

Officers found the man inside a truck in the Maryville Commons shopping center off Watkins Road.

When they approached the truck, they did not see him right away. They attempted knocking on the window's truck. The 67-year-old man did not respond.

An officer noticed a holster for a .45 pistol in the truck.

Police say the man was in the truck for at least two hours before authorities used an armed, protective vehicle to break the truck's window and pull him out.

He was taken to the hospital shortly after for further treatment.

Family members told Maryville police that the individual is an out-of-state relative who suffers from post-traumatic stress disorder.

Police have yet to release the man's identity.

The lockdown at the shopping center was lifted around 7 p.m. Sunday evening.

7:00 P.M. UPDATE: One man was detained after a standoff at the Target shopping center located off Watkins Road.

Maryville police believed he was armed and a threat to himself.

Officers were called to the scene around 5:15 p.m.

The shopping center is no longer under lockdown.

This is a developing story. We will continue to bring you updates.

PREVIOUS: Maryville Commons shopping center is on lockdown while police say a man is barricaded in the parking lot.

Police believe he is armed.

This is located at the Target off Watkins Road in Maryville.

Officers were called to scene around 5:15 p.m. They ask the public to avoid the area at this time.

The man is believed to be armed and a threat to himself, police said.

Several Maryville and Alcoa police officers are at the scene now.

This is a developing story. We will continue to bring you updates.