NASHVILLE, Tenn. -- Metro police said their crime lab needs major renovations and the city agrees, but police said while they are at it, they would like to add a full service DNA testing facility.

Video: Metro Police Look To Update Crime Lab

However, Channel 4 uncovered a study that reveals that a DNA lab may not be the best investment of the city's resources.

WSMV found a memo issued on Jan. 15, 2004, addressed to David Manning, the city's financial director at the time, that outlines the conclusions of Matrix Consulting Group, who did a study of the police department's request for a full-service crime lab.

The conclusion was that a lab was too costly and didn’t make sense considering the free services provided by the Tennessee Bureau of Investigation.

Police said that with one look around their crime lab, it is obvious that improvements are needed. The current lab location is a converted body shop and there are tests Metro police would like to do in-house that they can not currently perform.

"We don't have a separate firing range right now for shotgun testing, so we have to take our shotguns out to the range at the training academy," said Capt. Ben Dicke of the Metro Police Department.

But Metro is also pushing for an expensive addition equipment and manpower to do their own DNA testing.

"We are at a time in history where we desperately need that service. Our city has grown so much, it's become so large, we are handling such a high volume of work, it's more practical for us to do our own testing," said Dicke.

But is that really true?

Currently the TBI does all DNA testing statewide, and it's free to the individual cities.

But if Metro police assumed the role itself, a police spokesperson estimates it would cost about $90,000 a year out of the city police budget.

They argue it is a small price to pay in order to decrease turn around times for DNA samples, which are estimated right now at about eight weeks.

"I would say we would cut it at least in half," said Dicke.

But the 2003 study by Matrix Consulting Group found that TBI had high levels of service and reasonable turnaround times. The study was done at a time when TBI was even having troubles that they said they have since fixed.

"We did have a backlog problem in our labs, not just when it came to DNA, but when it came to other things as well. We have added 17 additional forensic scientists. We approved overtime. We did everything we needed to do to get those turn around times up," said TBI Spokeswoman Kristin Helm.

But for DNA testing to really hold up in court, a lab has to be accredited, which often takes several years, so Metro would still likely have to use the TBI's data until that happens.

The question remains: Is it really necessary and cost effective for Metro police to do its own DNA testing?

Channel 4 also talked to the Bradley County, Tenn., sheriff's office on Friday.

The sheriff there said his organization once tried to have a full service center but never had enough money to even get into DNA testing.

He said now that the TBI has added more staff and has improved its lab services, continuing to run a lab was simply an expensive duplication of services already available.

City officials said there is very little question that Metro's current lab facility will need to be renovated or moved all together because of the building's condition.

But they said the current administration will have to look at the chief's request for DNA testing more closely as well as all the projects approved by the past administration.