Arkansas man shoots 4 month old and 4 year old grandchildren

An Arkansas man, angry over a domestic dispute, has shot his 4 month old and 4 year old grandchildren, himself and one other person. From an article:

New details are emerging in a triple homicide/suicide in which a man allegedly shot and killed two of his grandchildren and his daughter's boyfriend before turning the shotgun on himself. (...) 

Witnesses said they thought Adams fired a warning shot into the air, but had actually shot Williams, who later died. 

Adams' daughter ran outside and tried to keep him from shooting inside the car, but he ran around the other side of the car and shot 4-month-old Chastyn Williams. The only motive they have so far in these two killings is that Adams didn't like Michael Williams, and had even referred to him and the infant as "being demons," Sheriff Brown says.

Adams then shot his 4-year-old granddaughter, Kierra Adams, in the back after chasing her, her grandmother and another child out of a bedroom in which they had barricaded themselves.