A 19-year-old faces murder charges after he witnessed a physical fight between his stepfather and mother before allegedly shooting and killing his stepfather, according to Fort Worth Police.

On Sept. 15, Fort Worth police responded to a shooting at 6340 Sloop Street in Fort Worth, according to an arrest affidavit obtained from the Fort Worth Police Department. Officers found a man, later identified as 40-year-old Kendrick Malone, shot on the scene, police said. He was taken to the hospital, where he died from his injuries.

Investigators found that 19-year-old Eric Titus III allegedly shot and killed his mother’s husband, Malone, after witnessing a physical altercation between the victim and his mom, police said.

Witnesses said Malone and his wife had been arguing and physically fighting over infidelity, the affidavit states. The fight involved “pushing, shoving, kicking, and open-hand hits and grabs from both the wife and Kendrick,” according to the affidavit.

As the argument began, Malone sent their youngest upstairs and continued arguing and fighting in the bathroom of their bedroom, officials said. As their children heard them arguing they came down to their bedroom to prevent them from hitting each other, the affidavit states.

The argument then lessened to verbal insults and yelling, witnesses told police. Malone was standing at the foot of the bed, and his wife was at the head of the bed when she saw her son, Titus III, shoot Malone from the doorway of the bedroom, the affidavit states. Another witness confirmed they saw the suspect shoot Malone while trying to de-escalate the argument.

Titus III fled the location, officials said. He later surrendered to police, according to his lawyer.

He was later arrested and charged with murder in connection with the incident, officials said.