Detectives and prosecutors will explain how to overcome barriers to solving domestic violence homicides using a 2007 cold case as a model at a University of Colorado Denver conference next week.

It took four years from the time Longmont resident George Ruibal beat his live-in girlfriend to death before murder charges were finally brought against the man authorities suspect from the day they found Dana Pechin's severely battered body in Longmont. A year later he was convicted in a Boulder courtroom and sentenced to prison.

Seventeen experts, including Longmont detectives, Boulder Medical Examiner Dr. Michael Arnall, and Boulder District Attorney Stan Garnett, will explain why it took so long to solve the Ruibal case and the grueling investigation they conducted to bring the case before a jury.

The public is invited to the all-day Tuesday conference beginning with 7:30 a.m. registration at the Denver campus' Lawrence building, 1340 Lawrence St.

Dale Siegrist, sister-in-law of victim Dana Pechin, and Robert Wells, who found the body of his murdered brother Sid Wells 30 years ago, will describe their experiences during the conference.

"We're going to walk through the case," said Barbara Paradiso, director of the Center on Domestic Violence at CU Denver. "There are lots of challenges to solving domestic violence cases."

Domestic violence murders can be tough to prosecute because the evidence key to solving homicides like fingerprints and semen aren't always telling because the killer lives with the victim.

Compounding the suffering for families of victims, the suspect is often the victim's husband, who later wins custody of his children, even when he has battered the children in the past, Paradiso said.

"It's a pretty horrific experience for families," she said. "The family is left with this person that they think killed their daughter and that they are afraid of and he gets custody of his children. There isn't room for healing when the kids are still living with their mother's killer."

Speakers will include former Denver homicide Lt. Jon Priest, a nationally recognized homicide investigator and Denver District Attorney Mitch Morrissey, who supervised prosecutions of 100 rape and murder cold cases.

"Mitch is one of the foremost experts in solving cold cases in the country," Paridiso said.

The FBI reports that one out of three murders become cold, or go unsolved for more than a year. Colorado has 1,525 cold case homicides dating back to 1970. For each unsolved murder, seven to 15 family members, friends, classmates, co-workers, neighbors and witnesses are deeply affected.

Kirk Mitchell: 303-954-1206, DenverPost.com/coldcases or twitter.com/kmitchelldp