Take a rare look inside HPD’s Homicide Division where up on the sixth floor, detectives often talk passionately about their cases -- especially the ones they’ve been unable to solve.

But because there is no statute of limitations for murder, those unsolved mysteries really never go away.

And now they’re getting a fresh set of eyes.

“These cases are very challenging,” Lt. Craig Williams said. “The evidence is old, witnesses have moved on, different states, some of them have died, memories fade, some of them just don’t want to tell.”

Lt. Williams oversees HPD’s Cold Case Squad and some 3,000 cases.

He said calling family members like John and Gay Osdall and telling them an arrest has finally been made in their loved one’s case -- “That’s what it is all about,” Lt. Williams said.

The Van Osdalls’ daughter Christine, a two-time teacher of the year, was found murdered seven years ago by fishermen in a remote wooded area off Eldridge Parkway.

Sgt. Eric Mehl took over the case.

“The technology is now catching up with the bad guys,” Sgt. Mehl said.

Technology like DNA. In Christine’s case, detectives always believed Steven Michael Sherrill was the prime suspect.

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Christine Van Osdall

The two met using a video dating service. A month later Christine decided to end the relationship.

“She read him this break-up script, and he talked her into a face-to-face meeting,” Sgt. Mehl said.

She died that night.

Sherrill took off, but inside his apartment a crime scene investigator found a small leaf.

Seven years later, Sgt. Mehl searched the nation for a plant specialist.

“And I took him out to the scene, out deep in the woods, and he picked this green leaf and was able to match it up to the leaf that came out of the suspect’s apartment,” Sgt. Mehl said.

That tiny leaf and the technology of DNA helped convict Sherrill of the crime.

“We owe so much to him,” Gay Van Osdall said. “It has brought great peace to our lives.”

“I will tell you that the resources that Harris County, HPD and the state of Texas laid on this case was truly awesome,” John Van Osdall said.