A 20-year-old man shot his grandmother to death then killed himself in a Fishers neighborhood Wednesday, Hamilton County Coroner John Chalfin said.

Zachary Hileman and Debra Hileman, 73, had been involved in a family dispute when Zachary shot her then himself early Wednesday morning, Chalfin said.

Both died of gunshot wounds. Debra's death was ruled a homicide; Zachary's a suicide, Chalfin said.

Fishers police found the bodies shortly after 1 a.m. in the 12600 block of Ladson Street, a neighborhood near 126th Street and Cumberland Road, the Fisher Police Department said in a news release.

Officers were called to investigate a family disturbance.

Fishers Police Department Sgt. Thomas Weger said Thursday the shootings remained under investigation.

Contact IndyStar reporter Vic Ryckaert at 317-444-2701 or vic.ryckaert@indystar.com. Follow him on Twitter: @VicRyc.