Connor Betts

New details are emerging about the investigation into the August 4 Oregon District mass shooting that left nine people dead.

A friend of the Dayton gunman who killed nine people told federal agents he bought him body armor, a gun accessory and a 100-round magazine earlier this year, according to a court document unsealed Monday.

Law enforcement authorities say the shooter in the Oregon District attack had a history of obsession with violence and had expressed a previous desire to commit a mass shooting.

Dayton Police announced Tuesday the Federal Bureau of Investigation is taking over the investigation into the 24-year-old killer’s motives in the attack that left nine people dead and more than two dozen others injured.

At a press conference, an FBI special agent from the Cincinnati Field Office told reporters there’s still a lot of evidence to go through. 

The family of the 24-year-old man who shot and killed nine people on Sunday, outside Ned Peppers bar in the Oregon District has released a statement.

Bellbrook Police Chief, Doug Doherty read the statement to the press near a street blockade set up about three houses away from where the Betts family lives in Bellbrook.

In the statement read by Doherty, the Betts family said they "shocked and devastated by the events of Sunday morning in the Oregon District," and that they are cooperating with the Dayton Police Department and the FBI investigation.

Authorities are continuing to investigate this weekend’s mass shooting on East Fifth Street in Dayton's Oregon District. Police have identified the killer as 24-year-old Connor Betts from Bellbrook.

The shooting left nine people dead, including the gunman’s own sister. More than two dozen other people were wounded. One remained in critical condition Sunday night.

Dayton Police Chief Richard Biehl told reporters the killer wore body armor and a face mask when he opened fire using an AR-15-like assault rifle.