Scores of pending criminal cases and past convictions could be in jeopardy in the wake of revelations that a former Houston Police crime lab technician resigned after an internal investigation found evidence of lying, improper procedure and tampering with an official record.

Former DNA lab technician Peter Lentz worked on 185 criminal cases, including 51 murders or capital murders, according to letters sent out by the Harris County District Attorney's Office and obtained by the Houston Chronicle through an open records request.

"It's a mess," said Gerald Bourque, an attorney who has several cases in which Lentz tested the DNA evidence, including two capital murder cases, one of which went to trial earlier this year. "If you're not following protocol, there's potential for contamination, transference, all kinds of stuff."

This is the latest in a series of problems to surface in recent months at HPD. A city-commissioned study showed the department failed to investigate 20,000 crimes with workable leads.

Earlier this year, Harris County prosecutors identified nearly two dozen criminal cases that could be in jeopardy after they linked them to a Houston homicide detective fired for lying and conducting shoddy investigations.

The disclosure about the technician's resignation comes as control of the perennially troubled lab was transferred in April from HPD to a civilian-led board of directors.

Testing suspended

In 2002, forensic testing at the lab was temporarily suspended because of a number of serious management, employee and structural problems, including a leaky roof that for years dripped water on stored evidence. There was also a backlog of untested rape kits, which at one point totalled 6,600, and persisted until August 2013 when the work was outsourced. more