(NewsNation) — The jury selection process has begun in the murder trial of Lori Vallow, whose case has been “bizarre” from the beginning, according to a private investigator hired by extended family.

Vallow is an Idaho woman accused of killing her two children and conspiring to kill her husband’s previous wife.

Rich Robertson is a private investigator who has been tracking the case since the drive-by shooting of Brandon Boudreaux, the estranged husband of Vallow’s niece.

“When I first was approached about helping out on this case, I knew nothing about the people involved and it came to me like a fire hose of stories of cults and missing kids and just a bizarre story that I wasn’t sure what to make of,” Robertson said Monday on “CUOMO.” “When it first got going on this, it was hard to piece together. It was a complicated story of people.”

It’s been nearly three years since the remains of 7-year-old JJ Vallow and 16-year-old Tylee Ryan were discovered in their backyard in rural Idaho.

Both Vallow and her husband, Chad Daybell have pleaded not guilty to murder, conspiracy and grand theft charges in connection with the deaths of her children.

Vallow’s trial is scheduled to begin April 3. A trial date has not been set for Daybell, whose case was separated from Vallow’s by a judge.

Months after Vallow’s children went missing in September 2019, she was charged with felony desertion but didn’t tell investigators anything about where her children might be, KPNX-TV reported.

“It’s going to be hard for her to shift the blame to some unknown killer, so-called third-party defense, and they’ve already filed a notice of an alibi defense saying that her brother Alex Cox may have been responsible,” Robertson said. “But if that’s true and she knew nothing about it, then why was she misleading and and lying to the police at the time?”

Prosecutors also allege that Vallow was involved in the death of Tammy Daybell, Chad’s previous wife, who was found dead in her bedroom in October 2019. Though a coroner’s report initially ruled the death as natural causes, police came to view the death as suspicious.

“The case against Lori involving the death of Tammy Daybell I think is going to be more difficult,” Robertson said. “I’m interested to see what kind of case the state puts together that links her to having knowledge about, or certainly more than that, conspiring to kill, other than just having an affair with Chad Daybell. She could be having an affair and still not have been conspiring with him.”

NewsNation correspondent Alex Caprariello contributed to this report.