A former employee at a FedEx warehouse in Indianapolis shot and killed at least eight people at the facility in Indianapolis late Thursday night and then killed himself, authorities said.

Authorities identified the suspect as 19-year-old Brandon Scott Hole of Indiana, according to The Associated Press. Hole is a former employee of the company, a FedEx spokesman confirmed.

Paul Keenan, special agent in charge of the FBI's Indianapolis field office, said Friday that agents questioned Hole last year after his mother called police to say that her son might commit "suicide by cop". He said agents questioned Hole based on items found in his bedroom. He didn't elaborate on what those items were. No crime was identified and the FBI said it didn't identify Hole as espousing a racially motivated ideology.

Investigators searched a home in Indianapolis associated with Hole and seized evidence, including desktop computers and other electronic media, Deputy Chief Craig McCartt of the Indianapolis Metropolitan Police Department said. 

McCartt said Hole last worked for FedEx in 2020. He said he didn't know why Hole left the job or if he had ties to the workers in the facility. He said police haven't yet uncovered a motive for the shooting but added that police seized a gun from Hole last year.

It was the fifth mass shooting resulting in the deaths of at least four people in the as many weeks, following massacres at three spas in metro Atlanta, a supermarket in Boulder, Colorado, a Southern California office building and at a private home in South Carolina. It was at least the third mass shooting in the city this year, Indianapolis officials said at a press conference Friday.

President Joe Biden on Friday again called gun violence an "epidemic" in the US and renewed calls on Congress to bring gun reform legislation to his desk in the wake of the FedEx shooting.

"God bless the eight fellow Americans we lost in Indianapolis and their loved ones, and we pray for the wounded for their recovery,"  he said.

The president ordered US flags flown at half-staff as he did in the wake of recent shootings in Atlanta and Boulder.

Authorities said the suspect arrived at the FedEx Ground facility's parking lot around 11 pm Thursday and started shooting at people with a rifle, without an immediate confrontation. "He just appeared to randomly start shooting," said Deputy Chief Craig McCartt of the Indianapolis Metropolitan Police Department at a news conference Friday morning.

The man then entered the building, shooting at more people before killing himself.

Five people were taken to local hospitals, police said. Two others were treated at the scene and released. Of the deceased, four were found in the parking lot and four inside the facility.

The warehouse near the Indianapolis International Airport on the city's southwest side employs more than 4,500 and is the second-largest hub in the company's global network.

A witness told an NBC-TV affiliate in Indianapolis that he was working inside the building when he heard gunshots.

"I see a man come out with a rifle in his hand and he starts firing and he starts yellin' stuff that I could not understand," Levi Miller said. "What I ended up doing was ducking down to make sure he did not see me because I thought he would see me and he would shoot me."

Earlier authorities had asked people who had been unable to reach family members who worked at the warehouse to gather at a nearby Holiday Inn Express, adding that representatives of the chaplain's office of the police department would be there to assist them. At the hotel more than 100 people waited for news. Family members said FedEx employees aren't allowed to use their phones on the floor of the warehouse and hoped that was why they had not heard from their loved ones.

After a significant drop in mass shootings in the United States during a pandemic-hit 2020, this year has already seen several deadly cases.

Eight people were killed by a gunman at three Atlanta-area massage parlors in attacks that began the evening of March 16. Seven of the slain were women, and six were of Asian descent. Police charged a 21-year-old white man with the killings.

About a week later, on March 22, a shooter at a supermarket in Boulder, Colorado, killed 10 people, including a police officer who was the first to respond to the scene. The suspect bought a firearm at a local gun store after passing a background check. Investigators are working to determine the motive for the shooting and why the suspect chose the King Soopers grocery store.

On March 31, a gunman killed four people and critically wounded a fifth at a Southern California office building. He knew all the victims. Apparently before opening fire, he chained shut the gates to two entrances, delaying police from getting inside. Among the victims was a 9-year-old boy who was found cradled in the arms of a woman believed to be his mother. The woman was the only survivor among those shot. The others killed were a man and two women.

On April 7 former National Football League player Phillip Adams shot six people. Robert Lesslie, a prominent doctor, was killed along with his wife, two of their grandchildren and two air conditioning technicians who were working at the their home. Adams also killed himself. His brain is now being examined for possible degenerative disease that has been shown to cause violent mood swings and other cognitive disorders in some athletes and members of the military.