Michael Waddell Johnson is on trial this week for allegedly beating and strangling his former common-law wife at her Salt Lake City apartment more than a decade ago.
Johnson, 65, is charged in 3rd District Court with first-degree felony murder for the Jan. 10, 1998 slaying of 40-year-old Cathy Cobb.
Prosecutor Katherine Bernards-Goodman told jurors during an opening statement that Johnson's DNA was found beneath the victim's fingernails.
Johnson also knew Cobb had been strangled. Bernards-Goodman said he told two people that Cobb was killed by "a Mexican," who was still at the apartment when Johnson stopped in to check on the woman.
In one version of the story, Johnson claimed he fatally stabbed the "Mexican," rolled up the body in a rug and put it in a Dumpster. But police testified Monday there was no sign of a violent struggle inside Cobb's apartment, located near 700 North and 900 West.
Defense attorney Nisa Sisneros told jurors police had conducted a poor investigation in which they focused on Johnson and never looked for other suspects.
She added that DNA testing showed the presence of "a second male contributor" in the material found under the victim's nails.
And despite an opinion by a Utah state medical examiner that Cobb died from strangulation, Sisneros said a defense expert will say the cause of death is uncertain, and that drug and alcohol use could have been contributing factors.
Cobb had cocaine in her system and her blood-alcohol measured 0.33 percent, which is nearly four times higher than legal limit for driving of 0.08.
"At the end of this case, you'll have more questions than answers," Sisneros told the jury. "And that, ladies and gentlemen, is reasonable doubt."
Cobb's body was discovered by her son, William Hall, on Jan. 12, 1998.
Johnson told police he last saw Cobb alive three days earlier when she left a party to go get her hair styled.
Police ended the investigation six months later by listing Cobb's death as "suspicious."
The case was reopened in September 2005 as part of a routine review of all so-called "cold cases" that was ordered by Salt Lake City Mayor Rocky Anderson.
