Authorities revealed on Sunday that a man, who allegedly killed six children and their two parents at a home in Houston, Texas on Saturday evening by fatally shooting them in the head, had a contentious relationship with one of the victims.

The suspect, 48-year-old David Conley, has a violent criminal history that dates back to 1988, according to court records, with an assault charge last month being the most recent incident.

Most of Conley's assault charges heavily involved 40-year-old Valerie Jackson, who was his former domestic partner. Back in 2013, he was arrested on an aggravated assault charge when he threatened her with a knife. He pleaded guilty and was sentenced to nine months in county jail, according to the Associated Press.

Conley is currently charged with capital murder for the deaths. Some of the victims were handcuffed and had been shot multiple times.

The victims were identified as Jackson, her husband Dewayne, 50; and their children Dewayne, 10; Honesty, 11; Caleb, 9; Trinity, 7; and Jonah, 6. Also killed was 13-year-old Nathaniel, who was believed to be Conley's son with Jackson.

Deputies received a call at around 9 p.m. on Saturday to conduct a welfare check to a home at 2211 Falling Oaks. They then called a High Risk Operations Unit once they found out that a man inside the house was wanted for a warrant for assaulting a family member.

When some of the deputies forced their way inside the home after they saw a juvenile's body from a window, Conley confronted them and began to open fire. Conley eventually surrendered an hour later without further incident, HNGN previously reported.