DNA firm wins praise for work on 'cold cases'

Salt Lake City police appear to have solved three "cold cases" in just one week, thanks in big part to a new company that does sophisticated DNA profiling.

Sorenson Genomics made a name for itself in 2005 when it helped the Thai government identify the remains of more than 1,200 people who died in the massive tsunami that struck on Dec. 26, 2004.

Sorenson Forensics, which just opened for business in October 2006, is an expansion of Sorenson Genomics. The company, however, is geared more toward law enforcement. It bills itself as providing casework services for federal, state and local crime laboratories. It was through the company's expertise in this area that Salt Lake's old cases appear to have been solved.

Dan L. Petersen, 44, was charged Friday in the 21-year-old stabbing death of Tiffany Hambleton.

Michael Jones, 40, was charged in 3rd District Court and arrested this week for the Feb. 24, 2004, slaying of 28-year-old Tara Cassandra Brennan. She was found strangled to death in the back seat of her car and was also stabbed in the neck and face, according to court documents.

Jones was linked to the crime because his DNA matched that found on the butt of a cigarette in Brennan's car, as well as a belt used to strangle Brennan, court documents state.

Also this week, Michael Waddell Johnson, 61, was charged in 3rd District Court with murder for the Jan. 11, 1998, strangulation death of Cathy Cobb.

DNA from fingernail clippings taken at the time of Cobb's death helped tie Johnson to the crime, court documents say.

Johnson was booked into the Salt Lake County Jail on Thursday and is being held on a $1 million cash-only bail.

What makes Sorenson so successful is that it has a more sensitive way of looking at DNA, said Tim Kupferschmid, forensics lab director.

"We are able to validate the latest technologies in a much more timely manner," he said.

Specifically in these two cases, the lab did a Y-STR analysis, a test that only looks for the Y chromosome in men. Sorenson Forensics is the only lab in the state that uses that test, Kupferschmid said.

"It's an extremely sensitive test," he said.

There is more than 99 percent certainty of a match using that technique, Kupferschmid said.