A Texas youth is behind bars after shooting and killing his own father inside his home, state authorities said.

Markus Xavier Benavidez, 20, is charged with one count of murder in the death of Markus Benavidez, 47.

The incident occurred on the night of July 13 at a residence on Greenwich Drive, Corpus Christi.

Around 11:30 p.m., a woman called 911 and reported that her son had shot her husband in the head, according to an affidavit obtained by local ABC and NBC affiliates.

Officers from the Corpus Christi Police Department reported that upon arriving at the scene they found the defendant outside the residence, between the garage and a white SUV. The man was surrounded until more officers arrived and was finally arrested.

Inside the home, police found the victim lying on a bed with a pool of blood under her head, according to the affidavit. An officer took the pulse of the injured man, but his heart was no longer beating. Paramedics pronounced him dead at the scene.

I had experienced hallucinations

The police read young Benavidez his Miranda rights shortly before midnight. During an attempted interrogation in custody, the defendant initially refused to answer questions and requested counsel, authorities said.

But then, as officers moved the accused son into a patrol car and prepared to close the door, he allegedly said, “I did what I did.”

The victim's wife told police that her son had recently been hospitalized for several days and had been experiencing hallucinations in addition to other drug withdrawal symptoms, according to the affidavit.

The woman added that she called a crisis helpline about an hour before the incident because her son said he was not feeling well.

While her husband retired to rest, the mother stayed awake with her son, according to police. The woman told investigators she saw him nodding his head and looking at the ceiling as if someone was talking to him.

As the night progressed, his son displayed increasingly erratic behavior, he told police.

At one point, while Mr. Benavidez was sleeping, the defendant took a pistol from the bedside table and fired. The woman said she tried to intervene after hearing the first shot, but then heard several shots during a struggle, and by then it was too late.