“Betrayal, greed and lust.” Did a hair mogul’s wife mastermind his killing?

More than eight years ago, his wife’s lover and an accomplice fatally stabbed celebrity hair stylist Fabio Sementilli on his Woodland Hills patio in what was made to look like a home invasion gone wrong.

The stylist’s daughter found his bloody body, called 911 and tried desperately to save him — to no avail.

Now, after two and a half months of court testimony, a jury must decide whether the dead man’s wife, Monica Sementilli, orchestrated his murder, or was duped by her jealous lover.

“This defendant was the mastermind behind her husband’s gruesome murder,” Los Angeles County Deputy Dist. Atty. Beth Silverman said in closing arguments this week. “This is a case about betrayal. It is a case about greed. It is a case about lust.”

Silverman argued in court that the evidence shows Monica Sementilli’s goal was to pocket $1.6 million in life insurance and avoid the complications of getting a divorce and start a new life with lover Robert Baker, a convicted sex offender and former porn star turned LA Fitness racquetball coach.

Jurors must decide whether Monica Sementelli, 51, is guilty of murder with special circumstances, conspiracy to commit murder and murder for financial gain.

“We aren’t her because she is a horrible mother,” Silverman told jurors. “We are here because she is a killer.”

As she publicy mourned the death of her husband — an executive at the hair-care giant Wella — Monica Sementelli sexted with Baker, even sending him nudes of herself taken the funeral weekend in Toronto, Silverman said.

She reminded jurors that, beyond the evidence of financial gain, hundreds of encrypted messages between the widow and her lover, there was also an accomplice to the killing who told jurors he had no doubts about who called the shots in the slaying.

Christopher Austin — who was convicted of second-degree murder in the killing of Fabio Sementilli — told jurors that he and Robert Baker stabbed the hairstylist to death after his wife left the door to the couple’s house unlocked.

Testifying as the prosecution’s star witness, Austin said he never heard directly from the defendant, but Baker told him Monica Sementilli wanted her husband “gone.”

“Everything he did he did after he got a text message, which told me he was talking to her via text message.” Austin testified. “I did not hear him talk to her on the phone.

But defense attorney Leonard Levine, in closing out the case, repeatedly said Austin never heard a single instruction from Monica Sementilli, and was instead duped by Baker. “There is nothing connecting Monica to the murder except Austin saying Monica called Baker,’ Levine said.

His client’s only misdeed was an affair, Levine told jurors. “For that she is responsible and will live with that for the rest of her life,” he said. “But adultery is not murder … Everything she did was to protect the affair, not to cover up the murder,” Levine said.

Prosecutors, he said, had dwelled on the lurid details of the affair, but that wasn’t evidence of murder. He said jurors needed to consider Baker’s testimony:

“I murdered him because I wanted her,” Baker told jurors. “She had nothing to do with it.”

The reason he killed the husband, Baker said, was because he was fed up with sharing her and living a life of secret liaisons. Baker is now serving a life sentence without the possibility of parole for the killing. Austin got a sweetheart deal, Levine said, and Baker had nothing to lose by telling the truth.

However, under cross-examination by the prosecution, Baker struggled to explain why he had provided multiple versions of the murder, including statements in a seven-page letter he gave to Monica Sementilli after he agreed to plead no contest to the Jan. 23, 2017, murder.

Baker said he and Austin found the hairstylist in a patio area and stabbed him several times with an eight-inch hunting knife. The hairstsylist’s body had seven sharp force wounds to his face, jawline, neck, chest, and thigh, along with two minor wounds on his left arm.

Baker said that at the time, he did not realize Austin had also stabbed Sementilli. They fled in the hair mogul’s car and dumped the knife in a hole and tossed their clothes near a bowling alley.

Baker acknowledged that he had tried to conceal Austin’s involvement in the slaying. It wasn’t until last October that authorities arrested Austin, an Oregon probation officer.

The slaying wasn’t their first attempt to kill the hairstylist, Austin testified. Monica Sementilli, allegedly messaged Baker that she was sending her husband to the store, and Austin tried unsuccessfully to target him as he got takeout food.

Baker said that for months, he and Monica Sementilli hooked-up secretly at his place and in vehicles. They also messaged constantly, exchanging sexual content, even in the wake of her husband’s death. They went to Las Vegas and Florida together.

Silverman asked Baker to explain why, on the day of the murder, he and Monica Sementilli both deleted encrypted messages on the Viber app on their phones. Baker answered: “it was glitchy.”

Following their arrest in June 2017, the pair were overheard discussing the phone and messaging app, and whether authorities could break in and read their messages in the aftermath of the slaying.

“They destroyed evidence, they deleted evidence, they tried to hide the planning behavior… so that they could have this new future together,” Silverman said in closing arguments.

Baker also admitted to buying burner phones, one of which was in Monica’s purse when the LAPD arrested them in her Ford Mustang GT six months after the slaying.

Silverman displayed a photo taken at Fabio Sementilli’s wake, where Baker can be seen sitting in the area where the killing occurred. Monica Sementilli is seen just feet away in the image. Silverman asked Baker whether he slipped the burner phone to her at the wake and he denied it.

But Silverman pointed out that Monica Sementilli had used the phone just days later in Canada, during funeral proceedings in Toronto — Fabio Sementilli’s hometown.

Baker also admitted under questioning that the widow sent him naked photos of herself with her wedding ring still on her finger. “Everyone grieves differently,” Baker declared.

While the home’s main bedroom was ransacked, the sylists $8,000 Rolex watch remained on his wrist, piquing the interest of detectives, LAPD investigators testified. Video surveillance captured two hooded men jogging up to the home before the slaying. Afterward, the men drove away in Sementilli’s Porsche and were recorded on another surveillance camera as they abandoned the vehicle 5 miles away.

About a month after the crime, LAPD Detective Ryan Verna testified that Baker’s DNA was tied to blood evidence at the crime. Baker’s DNA had previously been captured after he was convicted of lewd and lascivious conduct with a minor in 1993 and forced to register as a sex offender.

Investigators also noticed the killers had removed the home’s video recording system, which wasn’t easily found. As investigators tied the widow and the former porn star together, a forensic technology expert testified that he recovered instructions to Baker on how to access the home security DVR.

Silverman presented evidence that she argued showed Monica Sementilli watching a live feed of the area shortly before the killing to ensure Baker had a clear path to her husband. During the closing arguments, Silverman noted that when Monica Sementilli found out her daughter’s job interview ended early, she sent her to pick up new prescription glasses to delay her return home.

Levine and Blair Berk, co-defense counsel throughout the trial, portrayed their client as the victim of Baker. They told jurors there was no statement, no text, no recorded phone call that tied their client to the murder and she, too, was “duped into believing that Robert Baker didn’t do it.

In her final words to the jury, prosecutor Heather Seggell played back numerous recorded jailhouse conversations between the lovers. Separated and behind bars, the couple continued their relationship through three-way calls using a third-party number that connected them, was well as coded “kite” messages. They continued to talk, strip for each other and watch the other touch themselves, jurors heard. But they also talked.

When officers arrested them and placed them in the back of a police car together, the video recording system captured Monica Sementilli telling Baker, “deny everything and don’t talk.”