Robert Durst's Los Angeles murder case took an unexpected turn Wednesday, veering into the love life of former Westchester County District Attorney Jeanine Pirro.
Writer Lisa DePaulo was called to the witness stand during a special pre-trial hearing and put on the spot about Pirro's rumored romance with Cody Cazalas, the Texas homicide detective who investigated Durst for the 2001 death and dismemberment of neighbor Morris Black.
"Did you become aware Detective Cazalas and Jeanine Pirro had a romantic relationship?" Los Angeles County Deputy District Attorney John Lewin asked.
"Yes," DePaulo replied.
"Did you inquire when that relationship started?" Lewin pressed.
"She was vague," DePaulo replied, referring to Pirro, who split with her husband in 2007.
DePaulo said she knew the two were lovers because she spent many nights at Pirro's house while working on the ex- prosecutor's 2015 Durst book "He Killed Them All." She watched them retire to the same bedroom, she testified.
Under cross-examination by Durst's defense lawyer David Chesnoff, DePaulo was grilled again.
"Did Ms. Pirro have a picture of (Cazalas) in her house?" Chesnoff asked. "Was it out on display?"
Yes, Pirro had a photo, she replied, but it was mostly kept "in a drawer."
"When she heard Cody was coming, she'd take the picture, and she'd put it out?" Chesnoff asked.
"Yes," DePaulo answered.
It wasn't immediately clear why the alleged romance became a hot topic at the hearing.
Durst was arrested for Black's murder in 2001 but beat the charges, claiming self-defense.
Pirro and Cazalas ended up working side-by-side during the high-profile Texas case as New York officials reinvestigated the 1982 disappearance of Durst's first wife Kathie Durst and its possible connection to the 2000 murder of Durst's friend Susan Berman in Los Angeles.
Durst, 75, is now fighting charges he murdered Berman with an execution-style bullet to the back of her head. He has pleaded not guilty.
According to prosecutors, Durst murdered Berman to ensure her silence about Kathie's fate. They claim Berman covered for Durst for years and even posed as his missing wife to call in sick to work the morning after Kathie was last seen alive.
DePaulo testified Wednesday in a "conditional" exam that was videotaped for possible admission at trial if she becomes unavailable.
The judge has allowed several similar interviews to preserve testimony because the alleged motive in the case stretches back decades and involves many witnesses who are now elderly or infirm.
The preliminary hearing in the murder case that started Monday was paused before DePaulo took the stand and will resume in October, the judge previously ruled.
Pirro, 66, is now the host of the Fox News show "Justice with Judge Jeanine."
Pirro declined to comment through a Fox News spokeswoman.
DePaulo wrote several high-profile pieces about Berman's death for magazines like "New York" and "Talk." She testified about many of the associated interviews.
She said some of her sources didn't want to be named at the time but later changed their minds, giving her the green light to answer prosecutors' questions.
When Lewin asked where she got her early copy of the so-called "cadaver note" in the Berman case, DePaulo said it was Pirro who leaked it to her.
She said her book collaboration with Pirro hit the rocks when the TV host allegedly pressured her to include information she believed was inaccurate.
She eventually sued Pirro for breach of contract.
Pirro countered by claiming DePaulo drank "excessively" and fell asleep during work sessions — allegations DePaulo denied on the witness stand.
The legal battle reportedly ended in arbitration.