The 19-year-old gunman who opened fire at a FedEx site in Indianapolis, killing eight workers before taking his own life, was a former employee with a history of mental illness that led to his detention by law enforcement last year, police and FBI officials said on Friday.

The incident - the latest in a spate of at least seven deadly mass shootings in the United States over the past month - unfolded at a FedEx operations center near Indianapolis International Airport in Indiana after 11 p.m. local time on Thursday night, police said.

It lasted only a couple of minutes and was over by the time police responded to the scene, Craig McCartt, the Indianapolis police department's deputy chief, told a news briefing on Friday.

Witnesses described a chaotic attack, as the gunman opened fire with a rifle in the parking lot before entering the facility and continuing to shoot, leaving victims both inside and outside the building. Officers found the suspect dead of an apparent self-inflicted gunshot wound.

A FedEx spokeswoman and police identified the gunman as Brandon Hole, a former employee at the facility. McCartt told reporters the suspect was believed to have last worked at the plant in the fall of 2020.

Asked what brought him back to the facility on Thursday night, McCartt replied: "I wish I could answer that."

The FBI said in a statement that the suspect had been placed under a temporary mental health detention by Indianapolis police in March 2020 after his mother contacted law enforcement to report he might try to commit "suicide by cop."

A shotgun was seized from his residence then, and based on "items observed in the suspect's bedroom at that time," he was interviewed by the FBI in April 2020, FBI Indianapolis Special Agent in Charge Paul Keenan said in the statement.

"No racially motivated violent extremism ideology" was identified during that assessment, and no criminal violation was found, but the shotgun was not returned to the suspect, Keenan said.

The massacre is the most recent in a series of U.S. mass shootings that has again pushed the issue of gun violence to the political foreground.

Indianapolis - the capital of the Midwestern state of Indiana - alone has seen two mass shootings this year. In January, police say a teenager shot and killed four family members and a pregnant woman.

 

(Reporting by Maria Caspani in New York, Shubham Kalia and Kanishka Singh in Bengaluru, and Mark Hosenball in Washington; Additional reporting by Ismail Shakil, Steve Gorman, Barbara Goldberg, Susan Heavey, Njuwa Maina, Nandakumar D, Akriti Sharma and Akshay Lodaya; Writing by Joseph Ax; Editing by Steve Orlofsky, Rosalba O'Brien and Daniel Wallis) ((Shubham.Kalia@thomsonreuters.com;))