Chicago police say a teen boy is facing serious charges in the fatal shooting of his own mother. The most peculiar part of this incident is that authorities claim the shooting was seemingly at random.

Chicago Police Department authorities said before things went haywire, 17-year-old Davion Pryor was riding back to his South Shore home with his father and 7-year-old brother last Thursday afternoon after picking up the child from school.

The teen’s father told the police before they arrived home, Davion made a call to his mother, 43-year-old Tatanisha Jackson, to discuss someone drinking alcohol on the back porch.

The father told police they pulled in, Jackson unlocked the front door of the home and all hell broke loose.

Read more from ABC7 Chicago:

The teen’s father and brother, who witnessed the attack, told police it was as Tatanisha unlocked the home’s front door when Pryor opened the door and then pointed a gun at his mother and opened fire at nearly point-blank range. She was shot in the head four times.

Prosecutors said the father picked up his younger son and ran to safety ,where he called 911. They said they then heard five more gunshots from inside the home.

Authorities said after the shooting, the teen fled through the back door of the apartment. Security footage caught him running along Stoney Island. Police were able to track his location by his phone. Though, later that day, he turned himself in at the 3rd District police station.

Police confiscated the 9 mm firearm he used. Twelve bullet casings were recovered from the scene of the shooting. Authorities said the teen was on house arrest during the incident on previous aggravated battery charges from a July carjacking incident. Now, he’s being charged as an adult with first-degree murder in his mother’s killing, ABC’s report says.

This week he is due back in court for a mental evaluation. A Cook County judge denied his bond, citing the lack of motive in the shooting.

“This is very sad and tragic to this court,” said Judge David Kelly via ABC7 “The unprovoked shooting and killing of your mother in front of your father and brother.”