Defense attorney Bart Sheela conceded that 29-year-old Brandon Hayes killed his grandmother in her home in May 2009, but told a jury that his intention was not to rob her. Instead, Sheela said, Hayes strangled 73-year-old Eunice Cothron when she told him that she didn't have his birth certificate.

"He killed her, but he wasn't there to steal from her," Sheela said in his opening statement.

Hayes' father, Alan, found his mother's body on the kitchen floor on May 16, 2009. She had a towel stuck in her mouth and was cold to the touch, according to Deputy District Attorney Kurt Mechals, who said the victim had blunt force injuries to her face, neck and head, bruises on her arms and lacerations to her neck.

The defendant and a 22-year-old friend, Jeffrey Carl Reed, are charged with murder, robbery, burglary and carjacking.

A separate jury will hear the evidence against Reed, who met Hayes at a drug rehabilitation center, the prosecutor said.

Mechals told the jury that Hayes' entire family had disowned him because he consistently stole from them, but Cothron had a soft spot in her heart for her grandson and would give him money and do his laundry.

That all changed in mid-April 2009, when the victim got a temporary restraining order against her grandson because he took her car without permission and went through her personal items when he slept over, the prosecutor said.

A sheriff's deputy came upon the defendants at a Shell gas station near the victim's home around 4:30 a.m. the day of the murder and told Hayes the restraining order had become permanent, Mechals told the jury.

After killing Cothron, the defendants stole the victim's car and drove to the border near San Ysidro, Mechals alleged. The pair spent two days in Tijuana after the slaying, with Hayes spending a lot of money on a personal dancer, the prosecutor said.

Sheela said Hayes and Reed lived in Mexico because it was cheap and they could buy drugs there.

The attorney said the defendants traveled to Alpine the day of the killing so Hayes could retrieve his birth certificate, which he thought his grandmother had in her home.

Hayes initially sent Reed to Cothron's house to get the document, but when she told Reed, "I don't have it," both defendants returned to the mobile home, Sheela said.

When the victim told her grandson she didn't have his birth certificate, his whole world fell apart and he rushed in and killed her, then proceeded to steal her things, Sheela said.