Can someone shoot themselves in the side of the head with a shotgun?

Hurting mother is looking for answers. My son died from a shotgun blast to the side of the head. The rural sheriffs dept. said it was suicide. No autopsy was performed the whole investigation took no more than 3 to 5 hours. The gun was his great grandfathers gun, it was a long single shot breakover 12 ga shotgun, and had once before accidently discharged in the house. My son lived alone with my 9 year old granddaughter. If he commited suicide he did it in plain view of the house where my granddaughter would have went out looking for him and found him they had no close neighbors and it was a miracle my granddaughter didn't find him, you could see his body from the house. She called my mother to come get her and take her to school cause her daddy was not in the house. My mother and my sister found his body by the drive. My husband said it was an accident but I am grieving so much to think he could do that to his little girl and I am just searching for answers. Could he have done it.