Death penalty opponents are urging states to make sure DNA (search) crime labs can verify their results have put the right people behind bars.

And Texas -- home to the most executions in the nation -- may start heeding the call.

"I think every state should really take a look at what they're doing," said Texas state Democratic Rep. Kevin Bailey (search). "I would think every state should tighten their standards on DNA testing."

With the increased use of DNA testing in the criminal justice process -- 23 states require convicted felons to provide DNA samples -- the accuracy of test results has been called into question, particularly when used as evidence in death penalty cases.  

That means a lot of testing in Texas, which has put to death 301 inmates since 1982.

Bailey has sponsored legislation that requires accreditation of all Texas state DNA labs and calls for courts to throw out DNA evidence in cases where it is not tested in an accredited lab. New York and Oklahoma already require police lab accreditation.

The state House passed the bill on May 1. A Senate committee is expected to take up the debate next week.

The legislation comes as state lawmakers have started to express their frustration with the number of snafus at state DNA labs.

Houston's crime lab shut its doors in December after one man wrongly went to prison for a rape he didn't commit. The building apparently had a leaky roof that aided the contamination of DNA samples.

"It would be comical if it wasn't so tragic that these guys have a leaky roof," said Jim Marcus, executive director of the Texas Defender Service (search), who added rumors had circulated for years about shoddy work performed at the lab.

The Fort Worth Police Department is reportedly experiencing similar problems. That lab voluntarily closed in October after a DNA analyst was deemed unqualified and fired for not following procedure.

The Fort Worth lab is reviewing 100 cases. The Houston lab is re-examining about 1,400.

Death penalty supporters say that while more can be done to improve the quality of the work, a moratorium isn't the way to go.

"It's quite harmful to have a moratorium," said Kent Scheidegger, legal director for the California-based Criminal Justice Legal Foundation. "One of the reasons we have the death penalty is for its deterrent effect … you lose that when you have a moratorium."

Scheidegger noted Chicago's murder rate is skyrocketing, and blamed former Gov. Jim Ryan's last executive decision to halt executions until death penalty studies are completed.

As of Friday, Chicago counted 179 murders this year. The city finished 2002 with 646 murders, second to Los Angeles, which had 653. Chicago's per capita murder rate was America's highest among large cities.

Dianne Clements, president of the Houston-based Justice for All group, which also opposes a moratorium, said that in most cases DNA evidence used in capital murder cases is solid.

"A moratorium will do nothing but benefit the guilty and put more innocent people at risk," she said.

Others say a death penalty moratorium "casts too wide a net" in trying to get at the root of the problem, lumping faulty DNA evidence with other evidence that clearly demonstrates guilt.

"I think the problems with the DNA overall have been way overstated," said Kevin T. Meenan, the Casper, Wyo., district attorney and immediate past president of the National District Attorneys'  Association.

Meenan said DNA technology has aided the criminal justice process in ways never imagined.

"For the most part, DNA technology around the country has been a wonderful boost to the quality of investigations …it's a sound technology and it's only going to get better," he said.