A Cobb County judge has sentenced a 29-year-old man to life in prison for killing the mother of his child, who was in the house at the time of the murder.

Joshua Maurice Gibson was found guilty Friday of all charges he faced, including malice murder, said Kim Isaza, spokeswoman for the Cobb County district attorney's office. The jury deliberated 45 minutes.

Gibson shot Danielle Marshall in the head and left her inside her Powder Springs home on Jan. 13, 2013.

She was 23.

“This gruesome murder involved a level of premeditation that I’ve rarely seen before in all my years as a prosecutor,” said prosecutor Jesse Evans.”

Mugshot of Joshua Gibson (Cobb County Sheriff's Office)

Credit: Cobb County Sheriff's Office

icon to expand image

Credit: Cobb County Sheriff's Office

READCobb mother now charged with murder in beating death of son

The night of the murder, Gibson called 911, claiming he went over to Marshall’s house worried she hadn’t been responding to calls and texts, then became more worried when she didn’t answer and he heard their nine-month-old daughter crying inside.

With Gibson outside on a plastic chair, cops found Marshall's body in the fetal position on the kitchen floor shot once in the head, prosecutors said during the Jan. 31 opening statements.

READCobb mom gets max sentence for fatally poisoning her disabled son

Although Gibson was the “prime suspect” from the start, prosecutors said, there wasn’t firm enough evidence to hold him.

The case went cold after a year.

But a break came from examining phone records, which pointed to Gibson, who was arrested in 2015.

When judge Lark Ingram asked Gibson the standard question of whether or not he was satisfied with his defense attorneys, Gibson backhanded one of his attorneys, Isaza said.

READMan arrested for allegedly raping a student in a Kennesaw State dorm

That was Thursday, the day before he was sentenced.

The trial resumed, but the judge ordered that Gibson be removed from the courtroom because he was shouting over the state’s final witness.

After finding out he would spend his life in jail without the chance of parole, Gibson was told to sign the sentencing form.

Instead, he drew a crude image of the male anatomy and a lewd outline of a woman on the signature line of the public record.

Like Cobb County News Now on Facebook | Follow on Twitter

In other news...

Teen Set to Testify In Rape Trial Found Dead