Deputies say the man, James Ayala, was fatally shot around midnight in Katy right before his killer took his own life outside a Harris County Sheriff's Office substation.
Ayala's family says they do not want to talk right now, but did tell us a little more about him.
Related: Alleged gunman kill himself outside sheriff's substation after shooting in Katy
His brother says the victim served in the Army, and leaves behind his five children. His family described him as a good man, and says they are devastated by his passing.
Ayala was shot and killed at a home off of Katy Briar Lane, near Morton Road and Madison Road.
Detectives say a 17-year-old man found out his girlfriend was cheating on him with the victim, and asked the couple to come over. The two did, going to Darian Mitchell's home.
That is when Mitchell says he watched his friend, the 17-year-old accused gunman, kill Ayala.
"When he shot him, his girlfriend started screaming and then he ran," Mitchell says. "And then he shot again, and then everyone started coming out and screaming."
Deputies say the murder suspect went and confessed to his mother what had happened. She drove her son to the HCSO substation off of Clay Road to turn himself in. That is where the boy pulled a gun out and shot himself in the head as his mother and a deputy watched.