SAN DIEGO — Jury deliberations began Tuesday in a lawsuit that claims a woman found hanged at a San Diego-area mansion didn’t kill herself, but was slain by her boyfriend’s brother.

Deliberations began in the wrongful death lawsuit filed by the mother of Rebecca Zahau, who on July 13, 2011, was found hanging from a balcony in the Coronado home of her boyfriend, wealthy pharmaceutical executive Jonah Shacknai.

Zahau, 32, was the only adult known to have been present two days earlier in the mansion in the beach resort city when Shacknai’s 6-year-old son, Max, suffered brain injuries in a fall from a staircase. Authorities said Zahau died shortly after receiving a voice mail that said the boy’s condition had worsened and he wasn’t likely to survive.

Max died several days later. His death was ruled accidental.

Zahau was found naked and had rope around her wrists and ankles but San Diego County authorities concluded that she killed herself. Investigators believe Zahau loosely bound her wrists, took one arm out and put both arms behind her back before tightening the noose. Investigators said footprints on the dusty balcony and DNA on a knife, rope and bedposts helped them reach the conclusion.

Shacknai’s brother, Adam Shacknai from Memphis, Tennessee, had come to California after his nephew was injured and was staying in the mansion’s guest house.

He called 911 after finding Zahau and cutting her down.

However, the lawsuit alleged that Adam Shacknai sexually assaulted Zahau, killed her and staged the hanging.

In closing arguments, the defense said there was no physical evidence linking Shacknai to the crime scene and none of the 29 witnesses who testified in the case said he was in the house the night Zahau was believed to have died.

“Plaintiffs argue that he’s in the vicinity, therefore he must be guilty. That’s not evidence,” defense attorney Daniel Webb told jurors, the San Diego Union-Tribune reported.