Nashville leaders began grappling with the web of costs that come with police body cameras Monday, kickstarting what could be a lengthy debate over millions of dollars and constitutional rights in the criminal justice system.

District Attorney Glenn Funk called a meeting with Metro Council members, law enforcement and other stakeholders to discuss the mammoth undertaking ahead. Funk used state funding to hire consultants, who assessed potential funding and staffing needs facing the city once the police department deploys 3,240 dashboard and body-worn cameras.

Money has already been set aside to buy the body cameras, and a contract was finalized in August. But Funk and Nashville police Chief Steve Anderson have long predicted the camera launch would require millions of additional dollars for new staff and technology.

The public meeting formally brought the issue to city hall.

Funk said it was essential to review and manage the camera footage with care. He said cutting corners could amount to violating the Constitution.

"When body cameras go on, they create evidence in every case, and that creates constitutional responsibilities for every institution in the criminal justice system," Funk said.

"This is not something that we can launch and figure out as we go along, because the day that the body cams hit the street, the next day somebody is in jail. And the next day, somebody's going to court."

Consultants Paul Wormeli and Kay Chopard Cohen said the cameras would produce about 12,960 hours of footage per day, and they estimated that about 10 percent of that would figure into criminal cases.

High cost of implementing body camera policies

How much it will cost to process that footage depends on policies from the district attorney's office, the police department, the public defender's office and other parts of the criminal justice system.

By one estimate, the district attorney's office could need to hire 248 new people to review the footage. Under that estimate, personnel and technical costs could run up to $30 million.

Funk said a more conservative estimate that limited the types of cases where prosecutors review footage suggested his office would need $14.5 million and 107 new employees.

The public defender's office and arms of the courthouse would need their own pots of funding. The consultants created a tool to help estimate costs depending on how much footage each office decides to handle.

Wormeli and Cohen talked to officials in several other cities to determine how much Nashville should budget to support body cameras.

"In most jurisdictions, what they have estimated is far less than what the cost turned out to be," Wormeli said.

"Today, we've heard about the DA's office, the public defender's office, the criminal court clerk's office, the courts themselves all needing substantial additional ongoing money, and we certainly haven't ever had that tallied up," said At-large Council member Bob Mendes, the council's budget chair. "Once you add together the different departments for the full rollout, it's very expensive."

Mendes said body cameras should be rolled out in phases, with a series of small batches being deployed over time, so that the funding wasn't needed all at once.

Mendes said that, moving forward, the agencies would need to set formal policies so the Council could assess a realistic financial landscape.

Failing to fund the body cameras on the back end could create an opening for lawsuits and other liabilities, the consultants said. Funk added that the consequences could stretch beyond the courtroom.

"Under-funding will undermine criminal defense in this city and worst of all, it could erode public confidence in law enforcement," he said.

Reach Adam Tamburin at 615-726-5986 and atamburin@tennessean.com. Follow him on Twitter @tamburintweets.