In a chilling case of jealousy and greed, Las Vegas detectives found themselves unraveling a murder mystery after a mummified body was discovered in the desert.

The grim find was made on May 28, 2008, when a motorcyclist stopped along a roadside near Las Vegas and stumbled upon the corpse in the sand. This pivotal moment was detailed in an episode of The Death Investigator with Barbara Butcher, which airs Saturdays at 9/8c p.m. on Oxygen.

“It was clear to me right away that the body had been exposed for several days,” explained Detective Mark McNett from the Las Vegas Metropolitan Police Department. “The intense sun and dry conditions had caused the skin to darken significantly.”

The victim, a woman clad in pajamas and socks, lacked any form of identification. A towel was wrapped around her neck, concealing a wire ligature that had been used to strangle her.

The absence of blood at the scene suggested she was killed elsewhere. The manner in which her body had been disposed of was telling. “It was clearly the work of an amateur,” McNett noted. “They simply dragged her and discarded her like refuse. It’s infuriating.”

Results from the medical examiner

Maria’s autopsy revealed petechial hemorrhaging and a broken hyoid bone, both evidence of strangulation. Maria’s back was covered in bruises, a sign that blunt-force trauma occurred at or near the time of death. 

“In order to bruise, you have to be alive,” Butcher explained. “You have to have circulation.”

The autopsy also showed that Maria’s body had been covered in lye, which can accelerate decomposition. 

Detectives canvas Maria Marino’s inner circle

Police learned that Maria’s father, Alfred Ross, had moved to Las Vegas in the 1980s from New Jersey and started a successful fire and safety business.

“Al had this dream that we all can live together to be one big, happy family,” said Maria’s son Joseph Marino. “But he had a dark side. He pulled guns on his family members.”

Alfred’s bent for violence led investigators to consider him a possible suspect, according to The Death Investigator with Barbara Butcher. But after a thorough search of his house and vehicle, detectives switched their focus. 

“We discovered that Maria was the favorite daughter,” Clark County Deputy Assistant District Attorney Michael Schwartzer. “She was the one that Al entrusted with the business…and with the money for the family.”

Favoritism can foster resentment and jealousy. Police dug deeper into the relationship between Maria and her sister, Dolores. They learned that the siblings were constantly at odds.

“They always had a contentious relationship from a very young age,” said Rosemarie. “Dee’s contention with Maria was, ‘Why do you have access to daddy’s money?’”

Police focus on Dolores Penardo

Dolores and Richard refused to talk to detectives during the course of the investigation. But their history raised a red flag.

Detectives learned that the couple “had had interaction with the criminal justice system,” said Clark County Chief Deputy District Attorney Giancarlo Pesci. “A lot of petty crimes.”

Then, detectives got a break. James Ray, a Las Vegas junkyard owner with a lengthy criminal history, told police that his son’s ex-girlfriend reached out for help to dispose of a dead body.

That woman was Stefanie Petrozzino, Dolores’ daughter. Ray told police that he’d heard that the body was dusted with lye and dumped in the Mt. Charleston area. He also mentioned the wire ligature, a fact that hadn’t been disclosed.

Investigators turned their attention to Stefanie who’d had a number of previous scrapes with the law. Stefanie had a transient lifestyle, and she occasionally stayed at her grandfather’s house.

Investigators questioned Stefanie, and she denied having anything to do with her aunt’s death. Police didn’t have enough evidence to make an arrest.

Cold case gets reinvigorated

The case went nowhere for three years. At the time of Maria’s murder, Dolores’ son Bobby Petrozzino was in prison, and he was reluctant to speak to police.

Investigators zeroed in on recorded jailhouse phone calls between Bobby and Dee in late May 2008. One vaguely referred to a problem at home being solved. After that conversation, Bobby was released and lived with his mother. 

In 2011, Bobby was back behind bars. With his wife pregnant at home, he told police what he knew about Maria’s death, according to The Death Investigator with Barbara Butcher. 

Based on Bobby’s interview, detectives discovered that Maria was going to cut Dolores out financially from the family business.

The sisters were fighting at Alfred Ross’s house when Dolores grabbed a fire extinguisher and beat Maria with it. Dolores called out for help from Stefanie, who strangled Maria with a speaker wire.

Dolores convinced Richard to help load the body into a vehicle. Stefanie drove around for two days with Maria’s body in the car while trying to find someone to help her dispose of it. 

Richard eventually drove to the Mt. Charleston area of the desert, where they dumped the body and covered it with lye to destroy evidence.

“Even for Las Vegas,” said McNett, “the circumstances around the death of Maria Marino were very shocking.”

Three family members arrested for Maria Marino’s murder

In December 2012, Dolores, Richard and Stefanie were arrested. “The motive in this,” said Schwartzer, “was greed and jealousy.”

Richard Penardo pled guilty to accessory to murder and conspiracy to commit murder and was sentenced to two to five years. 

Dolores Penardo pled guilty to voluntary manslaughter and received six to 16 years in prison. 

Stefanie Petrozzino took a plea deal for second-degree murder. She was sentenced to 13 years to life behind bars.

Learn more about the case on The Death Investigator with Barbara Butcher, airing Saturdays at 9/8c p.m. on Oxygen.