MINNEAPOLIS — Court documents show a Minnesota man bought the shotgun he used to kill his family and himself just days before the shootings.

Police said 48-year-old Brian Short fatally shot his wife and three teenage children in their Greenwood home before turning the gun on himself. Officers found them Sept. 10 during a welfare check.

Applications for search warrants filed in Hennepin County court show that investigators found the purchase paperwork for a 12-gauge shotgun.

According to a press release, the warrant said the gun was bought at a Gander Mountain store in Eden Prairie on Sept. 6.

Documents said the owner’s manual to the shotgun was found near Short’s body in the garage. The documents also show investigators are looking for a suicide note, but haven’t found one yet.