A Houston crime-scene investigator made errors in 65 cases - including 26 homicides and five officer-involved shootings - since 2015, according to an audit of work at the Houston crime lab.
Defense attorneys have been notified about the problems, the Harris County District Attorney's Office announced Wednesday.
Depending on the scope, the evidence problems could jeopardize prosecutions of key cases.
It is the latest in a string of evidence problems that have forced the district attorney's office to review hundreds of cases in the past year.
"Defense lawyers are going to have a chance to determine for themselves the relevance of these errors or omissions," First Assistant District Attorney Tom Berg said. "Because most of these cases have not yet been fully adjudicated, we won't speculate on the possible impact, if any."
The audit of the Houston Forensic Science Center reviewed 88 cases handled by the officer, and found that 65 had incomplete document and 32 had administrative errors. In eight cases, evidence had been misplaced, according to a press release from the district attorney's office.
The investigator has been reassigned to a patrol position in the Houston Police Department, according to the DA's office. A supervisor who did not notice the problem has been removed from duty "temporarily," the press release said.
Harris County has been beset in the last year with a series of scandals involving forensic evidence – partly exposed by whistleblowers and partly uncovered by county officials who have audited procedures in an effort to improve procedures or investigate potential innocence claims.
In July, 298 wrongful convictions were identified as part of an ongoing audit of Harris County convictions that had been won based only on roadside tests or circumstantial evidence and later were discovered not to be illegal drugs in formal lab testing.
That same month, the city of Houston's independent crime lab identified problems uncovered in an audit of crime scene unit investigations that might have impacted officer-involved shooting cases.
Then in September, the Harris County District Attorney announced the office was reviewing hundreds of cases after revelations that officials at the Precinct 4 Constable's office had improperly destroyed evidence.
In January last year, Texas criminal justice organizations statewide also began to review cases that relied on an outdated method for calculating the odds that a particular person left DNA evidence at a crime scene – including some 24,000 cases in Harris County.
And a Harris County lab analyst was dismissed following revelations that she'd lied about her credentials, spurring a review of her cases.
This story is developing. Check back for new details.