The West Valley City man charged with the 2011 murder of 69-year-old Evelynne Derricott will stand trial, following a preliminary hearing in 3rd District Court Friday.
Rogelio Diaz, Jr. faces charges of first-degree felony murder, first-degree felony aggravated burglary and second-degree felony theft.
During the hearing on Friday, Chief Deputy Tooele County Attorney Gary Searle and Diaz’s attorney, Edward Brass, examined and cross-examined Tooele City Police Detective Chris Thompson and, briefly, forensic technician Rebecca Kay. The hearing revealed more details into the investigation of Derricott’s murder and the efforts leading to the arrest of Diaz.
Diaz was arrested in May after Tooele City police used familial DNA testing, a technique that matches samples of DNA evidence to relatives in the state’s DNA identification system. Once a family match is identified by the state crime lab, the police department narrows the list of suspects through other investigative means.
When Thompson entered Derricott’s split-level home on Havasu Street on Oct. 7, 2011, the investigation into cause of death was still underway, he said. A friend had come to check on Derricott and found her dead inside her Tooele City home.
Upon entering the home, Thompson said Derricott was found on her side, facedown on the stairs to the upper floor. Her head was pointing upward and there was blood on the wall behind her.
Derricott was wearing a hooded sweatshirt and Thompson said investigators found there were several holes in the hood. Searle asked if there were signs of trauma when officers pulled the hood back and Thompson said it was difficult to tell immediately because of the matting of her hair and the blood.
At the top of the stairs, officers found a claw hammer covered in red and brown stains, according to Thompson. When Searle asked if the initial thought was homicide, Thompson said yes.
While searching the home, investigators found the sliding door in the kitchen at the back of the house was unlocked, Thompson said. A door in the back of the garage appeared to have been pushed open; several items were knocked over and there was a partial footprint on a ladder inside the garage.
Investigators found Derricott’s car was missing from the garage, Thompson said. The following day, relatives noticed that Derricott’s cell phone and wallet were also missing from the residence.
Thompson said Tooele City police were able to find the general location of Derricott’s cell phone after it was “pinged” by the service provider. The search led officers to Kearns, near the Olympic Skating Oval, where they didn’t find Derricott’s phone — but did find her car, on a side street just west of the skating oval.
Two days after finding the missing car, police were able to locate the cell phone between two homes in Kearns less than a quarter mile from where the car was recovered, Thompson said. A mixed DNA profile, containing DNA from Derricott and an unidentified male, was recovered from the hammer inside the home; the DNA of the unidentified male was also found on the car’s steering wheel.
Despite the DNA evidence, Tooele City police could not find a match in any databases and the investigation ground to halt after “many” different suspects were ruled out, according to Thompson. After attending a conference on forensic techniques in 2014, Thompson decided to try familial DNA testing, which led to a close family member of Diaz as the most similar profile in the 110,000 DNA entries in the state database.
Thompson said the next step was building a family tree around the similar DNA profile and eliminating relatives who were unlikely to have committed the crime. Family members were removed from suspicion for reasons that included those already in the DNA database for prior felonies and those who were outside the country at the time.
Tooele City police eliminated suspects until focusing on Diaz, who had a family member who lived in Tooele at the time of Derricott’s murder and received mail at an address in Kearns close to the streets where Derricott’s cell phone and car were found, Thompson said.
Detectives then began to attempt to obtain a DNA sample from Diaz to confirm or deny his status as a suspect in the case.
Police collected marijuana pipes from Diaz on two separate occasions but were unable to get a usable DNA sample from either, Thompson said. They also followed Diaz and stopped him for an infraction in an attempt to gather DNA from the pen he used to sign the paperwork with, which was unsuccessful.
Tooele City police were finally able to obtain DNA profiles from Diaz on a construction site where he was repairing a cinderblock wall in West Valley City, Thompson said. Detectives set up observation in a vacant apartment overlooking the construction site.
While under observation, Diaz removed his work gloves before heading to lunch and did not put them back on upon returning, according to Thompson. At that point, a detective went down and collected the gloves for DNA testing.
Later that day, Diaz placed an energy drink he had been consuming on the ground and drove away, Thompson said. The drink can was also collected for DNA testing and the profile matched that found on the hammer and Derricott’s steering wheel.
Diaz’s attorney, Edward Brass, questioned Thompson on his evidence collection, including the fact the department’s evidence bag was open to the elements. He also asked about DNA collection and fingerprinting on the outside of the car and if there was video or body camera footage of evidence collection inside the home or when the car was recovered.
Thompson told Brass that they did not wait for long after Diaz returned from lunch to see if he attempted to pick up his discarded gloves at the work site. Brass also questioned Thompson on the fingerprints found in the house, as none of the fingerprints were a match for Diaz.
Rebecca Kay, the forensic scientist at the Utah State Crime Lab, was questioned by Brass on the items she tested for DNA evidence. The items included the blood stain on the wall in Derricott’s home, her right and left hand fingernail clippings, the steering wheel and gear shift in her car and her cell phone; other forensic scientists tested over pieces of evidence in the case.
Following the examination of Kay, 3rd District Court Judge Robert Adkins ruled there was enough probable cause for Diaz to stand trial in the case. Diaz’s arraignment is scheduled for Nov. 15 at 9 a.m.