RALEIGH, N.C. — The competency of the North Carolina State Crime Laboratory to help police catch criminals or rule out suspects has become a key attack point for Republican Gov. Pat McCrory against the man ultimately in charge of the lab, his Democratic gubernatorial challenger Roy Cooper.

Ads by the governor and other Republicans have focused on problems raised in an outside review in 2010 that found lab staff withheld or misrepresented blood test results that could have helped defendants. McCrory’s ads also criticize Cooper for testing turnaround times at the lab, particularly on rape evidence kits.

What the GOP ads don’t say is that Cooper ordered the review, and that most of the problem cases it cited happened before he became attorney general.

Meanwhile, Cooper has come out with his own ad saying that he’s led the way in improving the lab and expanding its testing capacity. Cooper’s campaign also says he pushed to have lab operations accredited by two independent organizations.

“We fixed the problems at the crime lab, and Gov. McCrory knows that,” Cooper says in a TV ad pushing back on commercials by the governor and Republican Governors Association. But McCrory and the association ran new, separate ads late last week riffing on the Cooper commercial.

“Fixed, Roy?” the narrator says incredulously in McCrory’s ad. The RGA ad features local Republican sheriffs. Democratic sheriffs came to Cooper’s defense in another commercial this week.

McCrory, who has publicized endorsements from several nonpartisan police organizations, has tried to paint Cooper as a hindrance to crime solving.

“His handling of the crime lab has also been atrocious,” McCrory said while accepting the backing of the North Carolina Police Benevolent Association. “His failure to do his job has made it harder for these law enforcement professionals to do their job and keep us safe.”

Cooper oversees the laboratory, which helps investigators with DNA and blood testing and other evidence analysis. Lab scientists also provide expert testimony. The lab was part of the State Bureau of Investigation until recently.

These anti-Cooper ads fit with perceptions that Republicans are tougher on crime than Democrats and attempt to take the focus away from the continuing criticism McCrory faces for signing a law last March limiting anti-discrimination rules for LGBT people, a political expert says.

“McCrory had to find an issue that takes the conversation away from (House Bill 2), so I think this is kind of ready-made response,” said Chris Cooper, a political science professor at Western Carolina University, who is not related to the attorney general.

The attorney general ordered the 2010 review soon after an SBI agent testified the crime lab once had a policy of excluding some blood test results from reports offered to defense lawyers before trials. The agent’s testimony led to the exoneration of a man imprisoned nearly 17 years for a murder conviction.

The outside review ultimately recommended more scrutiny of 190 criminal cases handled by the serology unit from 1987 to 2003, when these kinds of blood tests were discontinued.

Cooper’s campaign points out that the attorney general led many other changes before and after the review.

Cooper removed the SBI director and lab director and has obtained funds to hire more lab analysts, and helped clear a statewide backlog of more than 5,000 untested rape evidence kits more than a decade ago, campaign spokesman Ford Porter said.

Still, McCrory’s ads cite a local media report last year that some rape victims waited two years for test results, although the report also said local police waited for months to submit evidence to the lab. Other media also have reported on testing delays, sometimes leading to dropped prosecutions.

The average turnaround time for all lab testing requests is 7½ months, according to Noelle Talley, spokeswoman for the Attorney General’s Office. That includes some complex investigations that require dozens of tests. Others can be worked in a matter of days, she said.

A McCrory TV ad featured a sexual abuse victim criticizing Cooper for lab wait times, saying he “can never be governor.”

Cooper responded with the daughter of slain State Board of Education member Kathy Taft. Paige Fuqua said her mother’s killer wouldn’t have been brought to justice without crime lab improvements by Cooper. Fuqua says McCrory is trying to “gain politically from the pain of victims and families. Governor, please stop.”

In 2014, the legislature transferred the SBI to a governor’s cabinet agency, leaving the stand-alone crime lab with Cooper.

The RGA’s ads suggest the SBI’s removal from Cooper was linked to the lab’s mistakes, but the proper location of the SBI had been debated well before the lab’s problems surfaced, and the legislative debate in 2014 centered on the SBI’s independence, not the lab’s problems.