A Clayton County jury Tuesday heard the first day of testimony in a murder trial for a man accused of beating his girlfriend’s mother to death in June 2011 – allegedly with his girlfriend’s help.

Latoris Antowyn Grovner faces murder, aggravated assault and aggravated battery charges in the death of Alena Marble.

Grovner, 22, also is accused of stuffing Marble’s body in the trunk of her car, parking it across the street from her townhome complex and leaving her to rot in the hot sun while cleaning up the scene. He then allegedly tried to use her ATM card to withdraw money.

Prosecutors say the convicted domestic batterer conspired with his 23-year-old girlfriend, Marble’s daughter Kajul Harvey, to eliminate Marble, 59, who disapproved of the couple’s relationship.

“Unbeknownst to her, a plan was being devised,” Clayton County Assistant District Attorney Deah Warren said of Marble. “As she was in the sanctity of her home, that defendant came through a door his girlfriend left open and bum-rushed her.”

But Grovner’s attorney, David White, characterized the attack as self-defense on the part of his client, whom he said only came to the apartment to visit his then-pregnant girlfriend.

“What (this) isn’t is straight-up murder,” White said. “This isn’t even felony murder. (Harvey) texted him to come in after leaving the door open. Ms. Marble met him at the door, and that’s when it went down.”

Marble’s body was found on June 4, nearly two days after that alleged encounter, after witnesses who saw blood trailing from the car called police.

According to prosecutors, Marble was beaten so badly she was unrecognizable.

“He beat her with his fists,” Warren said. “He beat her with a bottle. He beat her with a pot. He shattered the cartilage in her nose. There were so many lacerations on her face, her skull was exposed.”

For two days, Warren said Harvey and Grovner stayed at the townhome, leaving only once when he went to try to get money with Marble’s bank card from a nearby Bank of America.

White acknowledged a rift between Grovner and Marble, saying that she forced her daughter to abort at least one pregnancy she had with him.

“Ms. Marble called him and told him that she made her have the abortion,” White told the jury.

But Marble had reason for wanting to keep Grovner away.

He’d had his probation revoked for repeatedly violating the conditions of the protective order put in place after his conviction on battery and aggravated assault charges for cutting and severely beating Harvey in July 2009, according to court documents obtained by The Atlanta Journal-Constitution.

He was sentenced to a year in jail.

Harvey eventually had the protective order lifted, court records show, but family and friends who knew her said Marble still feared what Grovner might do.

“The relationship between him and my sister was volatile,” Marble’s brother, Eugene Donaldson, testified Tuesday. “She would tell me how threatened she was by him.”

Brittany Franklin, a close family friend, told the court that Marble anticipated an attempt on her life by Grovner.

“Tori always came up in conversation,” Franklin said. “She would say, ‘That (expletive) told me he was going to kill me.’”

The trial resumes Wednesday at 9 a.m., and Grovner remains in the Clayton County Jail.

Harvey, who was also named in the 11-count murder indictment, will be tried at a later date.