In March of a year ago, Hole's mother warned the Federal Bureau of Investigation about him.
The FBI said agents had questioned Hole previous year after his mother called police to say her son might commit "suicide by cop".
IN has had a "red flag law" allowing police or courts to seize guns from people who show warning signs of violence since 2005. "The shotgun was not returned to the suspect".
Indianapolis Police Chief Randal Taylor told The Times he wasn't sure if that sort of hearing even took place past year but police never gave him back the gun they took away.
"We know that we have a Hoosier family who cried out for help, knowing they had a child who required mental health treatment". "But it's good that we did".
According to police officials, Hole had been previously employed by the FedEx facility where the attack was carried out. It is unclear what caliber firearms he purchased, but generally, shotguns deliver greater terminal ballistics at close range than the commonly possessed intermediate cartridges fired from weapons such as the AR-15.
This photo released by the Indianapolis Metropolitan Police Department shows Brandon Scott Hole.
Indianapolis FedEx Shooting Suspect Used 2 Assault Rifles He Purchased Legally: Police
Among the dead are four members of the Sikh community in IN - home to an estimated 8,000 to 10,000 Sikh Americans.
Candlelight vigils were held for the eight victims of a mass shooting at an Indianapolis FedEx facility.
Speakers shared their own experiences on gun violence and called for officials to take action. The incident lasted no more than five minutes.
The victims of the attack have been identified as Matthew R. Alexander, 32, Samaria Backwell, 19, Amarjeet Johal, 66, Jaswinder Kaur, 64, Jaswinder Singh, 68, Amarjit Sekhon, 48, Karlie Smith, 19, and John Weisert, 74.
Posts on Brandon Hole's since-taken-down Facebook page appear to indicate he was a member of the "Bronies" community - a group of mostly adult men who are extreme fans of the kiddie toys and animated television show, the Wall Street Journal reported.
"We do not yet know the motive of the shooter, and we may never know for sure what drove him to do what he did".
"Given everything our community has experienced in the past - the pattern of violence, bigotry, and backlash we have faced - it is impossible not to feel that same pain and targeting in this moment", a statement released by eight Gurdwaras in the Indianapolis area read. "We expect that the authorities will continue their full investigation and share what they learn when they can, and they will take this into account".
Three killed, two wounded in shooting at Wisconsin tavern
Officials were investigating another mass shooting in Indianapolis, where eight people were killed at a FedEx warehouse Thursday. Somers is about 30 miles (50 kilometers) south of Milwaukee, not far from the Wisconsin-Illinois border.