It was an unusual find inside a former employee's office at the Houston Forensic Science Center at HPD headquarters.

"It became evident that this was evidence," said Dr. Peter Stout, President/CEO of the Forensic Science Center. "They didn't know what type of case it was, so it did take us some time to understand what this case was involved with."

It was DNA evidence from a 1998 rape case of a woman inside a nursing home. Blood stain cards and biological materials were in an envelope. They should have been frozen and stored properly in a lab.

"Somebody's office is certainly not now, wasn't at that point an appropriate place for evidence to be," said Stout.

Stout says the Forensic Science Center took the finding seriously. Luckily they learned the DNA results made it to where they needed to go. There was no impact on that 1998 sex assault case.

"This is troubling, and this is just what we know about," said Doug Murphy.

Murphy is President-elect of the Harris County Criminal Lawyers Association. He says there are still concerns with how the Forensic Science Center operates.

"This certainly underscores the problematic approach they've always taken," said Murphy. "It still concerns me to this day because the Forensic Science Center is the HPD Crime Lab with a different name, that's all that's changed."

But Stout says the center's come a long way since it took over the HPD Crime Lab. They have new computer systems to keep track of evidence. And if and when isolated mistakes happen, they're going to own up to it.

"We do what we can to repair from those errors, in this case it was one case, it's always a problem for any case, but errors we are finding now are more associated with individual cases not what happened in the past," said Stout.