Indianapolis police say a gunman who fired eight shots at FedEx’s warehouse bought two used assault rifles legally despite seizing a shotgun a few months ago.
Brandon Hole’s mother warned him of his mental state last March and police took a gun away from him.
However, he was later able to buy two assault rifles in July and September.
On Saturday, his family apologized for his actions.
The 19-year-old former FedEx worker was shot in the warehouse on Thursday before committing suicide just minutes before police arrived.
Four of the dead have been identified as members of the local Sikh community. Other victims include two 19-year-old children, a university graduate, and a father.
Police still do not know the motive for the attack.
Paul Kennen, special agent in charge of the FBI’s Indianapolis field office, said Hole’s mother called police last March and feared her son might attempt “death by police.”
The Indianapolis Star newspaper show, recorded officers arrested him and snatched his shotgun before.
Agent Keenan said the FBI interviewed him a month later but found no evidence of a crime and could not identify the hole as following an extremist ideology.
The assailant used two rifles in the attack, police said.
He fired randomly at people in the parking lot of the FedEx facility, killing four and seriously injuring four others before entering the building.
Indianapolis police said they could not provide details about where he bought the rifle as an investigation was ongoing.
President Biden called the Indianapolis shooting and other recent massacres “national embarrassment.”
Earlier this month, he announced the first steps to tighten gun control. These include the specific gun, ballast background checks, and efforts to legislate to support local violence prevention.