Salt Lake City prosecutors knew a component of convicting two men charged with severely beating a 17-year-old with a battle ax outside a Kearns home was proving the attackers lured their victim outside by posing as a girl sending text messages.

But they needed to see exactly what texts were sent and whose phone those messages came from.

Records extracted from cellphones confiscated after the arrests of Cody Jesse Augustine, 23, and Scott Tyler Stapley, 24, in 2008 showed that the men pretended to be a girl the victim had previously dated and promised sex if he came outside the home in the early morning hours to meet her.

The jurors who convicted Augustine and Stapley of first-degree felony attempted murder saw a transcript of the texts, helping prosecutors prove the men had planned their attack.

In an age when more crime is committed with social media, the Internet, cellphones and cameras as witnesses, digital evidence like that used in the battle-ax case is becoming more important than ever. It’s why experts at the FBI’s Intermountain West Regional Computer Forensic Laboratory, or RCFL, in Salt Lake City are seeing expanding caseloads and training more police officers on how to analyze cellphones for evidence.

The lab, which serves law enforcement agencies in Utah, Idaho and Montana, assisted 96 police agencies in the past year, said Michael Jensen, director of the Intermountain West RCFL.

“More and more PDs are using this as a resource. There is more awareness of the lab and what we do,” he said.

Located in an office building near the Gateway mall, the lab conducted 609 examinations in 2010. Examiners testified in eight court cases and trained 115 officers on digital forensic tools.

Whether it is a phone record proving a suspect was at a crime scene, photos of nude teenagers sent over cellphones in “sexting” cases, or photos on the hard drive of a child pornography distributor, experts at RCFS work on an endless variety of data. The work is a meticulous, sometimes painstaking process that can take days. But finding the right file can be key to making or breaking a case.

After obtaining a search warrant, examiners hunt for potential evidence by using software programs and different operating systems. They search for deleted, encrypted or damaged file information suspects may have tried to destroy.

The laboratory is assisting in two of Utah’s recent high-profile cases: The slaying of Ethan Stacy and the search for missing West Valley City mother Susan Powell.

Nathan Sloop, 32, and Stephanie Sloop, 28, are both charged with aggravated murder in the slaying of 4-year-old Ethan Stacy in May 2010. Stephanie Sloop was Ethan’s mother, and Nathan Sloop was his new stepfather. Charging documents allege the couple engaged in multiple acts of “severe abuse” between April 29 and May 8, which led to Ethan’s death, including “beatings, burning, drugging, isolating, malnourishing, leaving the child alone and unattended while suffering, and refusing to seek vital life-sustaining medical attention.”

The case is set for a preliminary hearing in November — where evidence retrieved from hard drives and phones by forensic examiners at the RCFL could be presented.

RCFL examiners have also helped in Powell’s case.

The 29-year-old disappeared Dec. 7, 2009, from her West Valley City home. Her husband, Josh Powell, has said he took his young sons on a late-night camping trip to Simpson Springs in Tooele County and when he returned his wife was gone. West Valley City police have called Josh Powell the only person of interest in his wife’s disappearance, but he has said his wife left on her own accord.

West Valley City police served a search warrant on the Powell residence on Dec. 9, 2009, and removed boxes, bags and a computer. RCFL examiners investigated the contents of that computer.