Murderers often plan their acts of violence. And, sometimes, victims are picked at random.

The Oct. 11 episode of The Death Investigator with Barbara Butcher delved into a chilling double murder in Las Vegas, leading detectives on an unexpected trail of evidence.

On April 16, 2012, 9-year-old Christopher Martinez recounted a harrowing tale to his teacher. He said his mother and sister had been slain, and his father, Arturo, had suffered injuries. Meanwhile, his younger brother Alejandro remained unharmed at home.

 “When we walked in,” said Las Vegas Metropolitan Police Department Homicide Detective Dean O’Kelley, “there was blood everywhere.” 

Arturo suffered severe head wounds and was swiftly taken to a hospital. His wife, Yadira, known affectionately as Yady, 38, lay on the floor with blunt-force head trauma and evidence of a sexual assault.

Their daughter Karla, a bright 10-year-old passionate about gymnastics, was found dead in a bedroom. “Like her mother,” O’Kelley stated, “her injuries were also extensive.”

Who were the victims? 

Investigators learned that Yady, who dreamed of being a lawyer, and Arturo came to the U.S. from Mexico seeking opportunities.  

Arturo worked in construction and as an electrician while Yady raised the children. Arturo eventually was able to open up a boxing gym. 

Though investigators had to consider domestic abuse, that was ruled out. Arturo’s head wounds were so severe they couldn’t have been self-inflicted. 

O’Kelley believed that Arturo was bludgeoned first and unconscious when his wife and daughter were killed.  

“It’s apparent,” O’Kelley said, “that the suspect never even knew [the boys] were there.”

What the autopsies revealed

As investigators processed the crime scene, the bodies of Yady and Karla were brought to the Clark County Coroner’s Office to be autopsied.

“We were looking for further evidence,” said LVMPD Homicide Detective Dean Raetz. “It might be on the bodies themselves.”

The analysis supported the investigators’ initial thoughts. “We confirmed that Yady was sexually assaulted,” Raetz explained. “Foreign DNA was discovered on her body.”

While investigating, police chased two leads—one involving Arturo’s former employee and another concerning unhappy neighbors—both of which proved to be dead ends.

“None of the usual suspects were adding up in this case,” said Las Vegas Review-Journal’s Mike Blasky. “People in the community were concerned.”

The search for the murder weapon

Police scoured the crime scene inside and out to find the murder weapon. They found a coat with blood on it in the bed of a truck parked in the driveway. 

Christopher, now an adult, recalled telling police that it didn’t belong to anyone in his family.

Investigators eventually found a bloody hammer hidden inside a cinder block outside the residence. It was sent to the crime lab for processing.

“It’s an exciting point in the investigation,” said Raetz, “because now you have a major part of your story.”

Still, a nagging question loomed in the wake of the unspeakable tragedy.“Why?” asked Yady’s brother Silver Olmedo. “They have no enemies.” 

Police learn of another nearby crime

On April 19, investigators learned that a woman was sexually assaulted the same night as the Martinez murders and close to that crime scene. 

“She was walking down the street in the direction of the Martinez house,” said Raetz. “She notices a black male across the street, and he started following her.”

The woman dialed 911 as she was walking. In a recorded call she’s heard saying “What is your problem?” Then she’s heard screaming.

During the assault she struck her attacker in the head with a rock. As police sirens drew close, the attacker grabbed her phone and ran in the direction of the Martinez house.

“He didn’t do a full sexual assault or leave DNA or semen,” noted Raetz. “But she had the rock in her hand still.” Blood on her clothes believed to belong to the attacker was later processed for DNA.

Video footage caught the man on tape as he followed the victim. He was wearing a jacket that matched the one found at the Martinez home. At the time, police believed he went from one crime scene to another.

“Killers like this, they have a pattern, a need to assault and torment someone,” said Butcher, “and it’s not always satisfied on the first assault.”

Bryan Clay emerges as a suspect

Investigators focused on calls made from the phone stolen from the woman. Ten days into the case, Bryan Clay, a man with a violent history, emerged as a suspect. 

“He had a woman who was pregnant with his child,” said O’Kelley. “He actually knocked her to the ground and attempted to abort the child by kicking her in the stomach.”

On April 27, Clay’s mother turned her son in, and he was taken into custody. Clay claimed he didn’t recall any attacks because he’d been drinking and taking drugs. 

In a recorded interview, O’Kelley challenged Clay. “No flashes of memory,” the seasoned investigator said, tearing up as he’d never done before. “Of what you did to a little girl with a hammer?”

Clay never confessed, but his DNA linked him to the murders and the sexual assaults. He was arrested for the crimes.

“There isn’t any question,” said Clark County Chief Deputy District Attorney Marc DiGiacomo, “as to who perpetrated these crimes.”

After five years of delays, Clay was tried and convicted in December 2017 of the murders and sexual assaults. He was sentenced to life in prison without the possibility of parole.

The Death Investigator with Barbara Butcher airs Saturdays at 9/8c p.m. on Oxygen.