The gunman who shot dead 14 people and wounded 22 others in a mass shooting at a post office in Oregon on Monday night has been identified.

Authorities said that T.J. Maxx is investigating the incident.

Maxx, 25, is an employee at the Post Office and has worked there for about a year.

He was one of two employees who responded to the call from the victim’s mother, who said she was going to the restroom when the gunman approached her and began shooting.

The mother said she tried to get help from Maxx but he was still shooting, according to a police report.

He also was shot in the head.

The gunman then opened fire on the Post office’s employees.

Police have not released a motive.

Maxy and another employee were wounded.

The rampage, which killed six people and injured 22, happened in a busy neighborhood near downtown Portland.

Authorities have identified three other people killed in the shooting.

Two of them were found dead in a parked car.

Another was found dead by firefighters in a nearby apartment building.

Police believe the gunman, identified as 25-year-old T.T. Sargeant, opened fire from a vehicle after killing a woman who called 911, the Portland Police Bureau said.

Police said the gunman is suspected of committing other mass shootings in the state.

Investigators found the truck used in the attack, which was registered to Sargeants mother, in an abandoned building on Interstate 84.

They said the vehicle had been reported stolen earlier this month.

Authorities are searching for other individuals who were at the location Monday night, including people who may have been involved in the previous incident.

The FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives are assisting.

A large crowd of people gathered at the scene.

Some were carrying signs that read, “This is for the victims.”

The Post Office has been on lockdown since the shooting and closed the doors.

The doors were open to the public until 10:30 p.m.

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The office reopened Monday evening.