The teenager who police say fatally shot eight people at a FedEx warehouse in Indianapolis this week legally purchased the two semiautomatic rifles he used, even though the FBI questioned him last year after a disturbing warning from his mother, police said Saturday.

Agents interviewed Brandon Hole a year ago after his mother told law enforcement that she feared her son might attempt “suicide by cop.” Hole, 19, took his own life after the FedEx shooting on Thursday.

Paul Keenan, the special agent in charge of the FBI’s Indianapolis field office, said agents found no evidence of a crime then.

But the Indianapolis Metro Police Department at the time placed the teen on a “mental health temporary hold” at a local hospital to assess his state of mind. They also confiscated a shotgun Hole had purchased within the previous 24 hours. The police report noted that the shotgun was seized from a “dangerous person,” The Indianapolis Star reported.  

The shotgun was never returned to Hole, Metropolitan Police Chief Randal Taylor told The New York Times. Yet the teen was nevertheless able to legally purchase two powerful weapons, which police described as “assault rifles,” last July and September, according to authorities.

The state’s “red flag” law was not used to keep firearms out of Hole’s possession. Such laws, which exist in at least a dozen states, bar people deemed a danger to themselves or others from owning guns.

It wasn’t immediately clear whether officials ever initiated a court action under the law to bar Hole from gun possession, according to Taylor, or if a judge may have ruled against such an action. In any case, red flag laws usually only temporarily restrict gun ownership.

Investigators are still seeking a motive for the devastating killings. Hole was a former FedEx employee.

Hole’s family on Saturday apologized for the tragedy.

“We are devastated at the loss of life caused as a result of Brandon’s actions; through the love of his family, we tried to get him the help he needed,” the family said in a statement.

“Our sincerest and most heartfelt apologies go out to the victims of this senseless tragedy,” the family’s statement continued. “We are so sorry for the pain and hurt being felt by their families and the entire Indianapolis community.”

Language has been amended to better describe the weapons used in Thursday’s shooting.