Update (1/26): This post has been updated to reflect a comment from Rockefeller's office on the timeline for introducing legislation.

Three years ago, the influential National Academy of Sciences released a scathing report broadly condemning the work of criminal labs in the U.S. Too often, the report found, forensic labs do subpar work and rely on unproven techniques such as analyzing bite marks or examining the markings on a bullet. As the report noted, sloppy forensic work has played a part in many wrongful convictions. (We've detailed other forensic failures in our ongoing series on the country's death investigation systems.)

The report and experts say the shortcomings could be addressed in part by a national forensic science agency that could rigorously test forensic science techniques to see if they actually worked. Another key reform from the report, once again widely endorsed by experts, would establish enforceable standards and set up a mandatory certification and accreditation process for forensic science professionals and labs.

The report's conclusions, which one legislator called "damning" and "terrifying," prompted a series of Senate hearings to examine ways to strengthen the troubled forensic science system.

So, three years on, where do things stand in Congress? Not very far from where they started.

Early last year, Senate Judiciary Committee Chairman Patrick Leahy, D-Vt., introduced a bill to implement many of the report's proposed reforms. The bill has moved little since then. When asked for comment, the senator's office said he is still discussing the bill with law enforcement but hopes the committee will consider it this year.

Experts say even if the bill passes in its current form, it would not implement a key recommendation. The bill proposes the creation of a national forensic science agency like the NAS report suggested but would put the new office within the Department of Justice. The report strongly advised that the new agency be completely independent from any existing department, especially the DOJ.

From the report:

[N]o existing or new division or unit within DOJ would be an appropriate location for a new entity governing the forensic science community... The entity that is established to govern the forensic science community cannot be principally beholden to law enforcement. The potential for conflicts of interest between the needs of law enforcement and the broader needs of forensic science are too great.

"[The DOJ] is the last place the NAS report wanted the agency, for the most obvious of reasons," said Marvin Schechter, a criminal defense attorney in New York City and former member of the committee that wrote the NAS report. "For over 100 years, forensic science in this country has been under prosecutorial law enforcement control, and it's been a disaster."

Harry Edwards, a law professor at NYU and co-chair of the committee that wrote the NAS report, said forensic scientists shouldn't work within law enforcement, "not because we do not trust law enforcement officials but because they serve different roles than scientists who are charged with assessing forensic evidence."

The establishment of a new forensic science agency in the Department of Justice would raise important questions about who would report to whom, who would pick the oversight committees and who would have the authority to approve or veto judgments by each group, Edwards said.

In a statement on Jan. 25, 2011, Leahy said there was simply not enough support for a wholly independent agency, which would impose too high a cost on taxpayers. The proposed forensic science office "capitalizes on existing expertise and structures, rather than calling for the creation of a costly new agency," Leahy said.

Leahy acknowledged the argument for independence, and as a result, his bill has a "hybrid structure." A Forensic Science Board of forensic and academic scientists, prosecutors and defense attorneys would make recommendations to the director of the forensic science office. Additionally, committees of scientists would look at each forensic science discipline -- from bite marks to blood spatters -- to figure out research needs and standards.

But Schechter said this layered system would only introduce more problems. "Because Leahy took [the national agency] out of an independent entity," he said, "he had to fit it into the DOJ like a square peg in a round [hole]. The result has been a chaotic if not twisted bill."

DOJ involvement doesn't have to be an either-or decision, said Peter Neufeld, a founder and director of the Innocence Project, a national organization that works to exonerate innocent prisoners and reform the criminal justice system. Neufeld said a national agency of forensic science should be a collective undertaking. A scientific agency with research experience, such as the National Science Foundation, could be in charge of setting forensic standards, and the DOJ could be in charge of accreditation, certification and implementation, he said.

While the Leahy bill has languished, Sen. John Rockefeller, D-W.V., is also considering legislation to mandate improvements to forensic science. In December, he held a hearing on the subject. (Here's the full video of the hearing and testimonies.) In a recent letter, the president of the American Statistical Association urged Rockefeller not to follow Leahy's approach and to instead create an independent agency.

Rockefeller has yet to propose a bill, but, according to a committee aide, he is hoping to introduce one this year.