OKLAHOMA CITY - Hundreds of families in Oklahoma County are waiting for justice for their loved ones. In Oklahoma County, there are 500 unsolved murders, some dating by to the 1950s. Mike Burke is the county's only cold case detective working, determined to solve them.

"It's something I enjoy and it's rewarding," Burke said.

Burke is a former Oklahoma City Police Homicide Detective and now works for the Oklahoma County District Attorney's Office. He came out of retirement to solve cold cases. Like the 2013 murder of 94-year-old Evelyn Goodall.

"To have something like that happen to her was kind of sad because she would have given the guy anything he wanted," said Jane Calton, Goodall's Niece.

Goodall was brutally assaulted and killed in her own home. Four years after her death, Burke developed new witnesses.

"Eventually we were able to get people who talked to us about a certain person in the neighborhood that stayed up late at night, used narcotics," said Burke.

The evidence pointed to Robert Hashagen, a CLEET certified police officer and the elderly victim's neighbor.

"We felt relieved, we really didn't think they would ever you know solve it but he just never gave up," Calton said of Burke. "We really appreciated him."

Advances in technology are helping Det. Burke solve cases. After five years of bad leads, Burke found his prime suspect in the 2001 Halloween night murder of Vera Gowers.

"Low and behold we get a cold hit on the case which is a CODIS hit," he said. "CODIS hit is a combined DNA indexing system that is run by the state and all the offenders from the penitentiary are put into this system."

Willie Hayden, Jr., was convicted of murder in Texas and currently serving time in an Oklahoma prison for beating a pregnant woman. He's now charged with Gower's murder.

"To have a guy that has been able to evade prosecution that long, it's a very wonderful thing," Burke said.

But for every win, there are more losses. Cases Burke may never be able to solve. 

"The hard part is we've looked for evidence on some of these really old cases and it's gone and there's nowhere else to look," he said. "Be assured that if we have something we are working on it and that we would love to solve it."

Willie Hayden, Jr. Is expected to be in court tomorrow for a preliminary hearing and Robert Hashagen goes to trial for murder in October.