NASHVILLE (AP) - Gov. Bill Haslam on Monday vetoed a bill that would require images that document animal abuse be turned over to law enforcement within 48 hours, saying his main concern is its constitutionality.

State Attorney General Bob Cooper last week said in a legal opinion that the measure would be "constitutionally suspect" because it could violate Fifth Amendment protections against self-incrimination and for placing burdens on news collection.

Haslam said the opinion is among at least three reasons he's vetoing the bill.

The second reason he gave was the bill appears to repeal parts of Tennessee's Shield Law without saying so.

"If that is the case, it should say so," Haslam said.

A third reason for the veto, Haslam said was that some district attorneys are concerned the bill actually makes it more difficult to prosecute animal cruelty cases, "which would be an unintended consequence."

A number of groups and celebrities have spoken out against the proposal they have dubbed the "ag gag" bill. They say the bill is designed to prevent whistleblowers from collecting evidence of ongoing patterns of abuse.

The Humane Society in 2011 secretly filmed video inside a training stable showing caustic substances being applied to Tennessee walking horses' legs and hooves, and the animals being beaten to make them stand. Trainer Jackie McConnell pleaded guilty in federal court in September.

"It's the wrong policy to punish the person who exposes cruelty, instead of the person who perpetrates it," Wayne Pacelle, president and CEO of the Human Society, said of Haslam's veto.

"We are grateful to Governor Haslam for hearing the clear voice of Tennesseans and ending this debate so emphatically."

Haslam later told reporters after speaking at a luncheon in Franklin that he understands farmers' concerns that tactics they use to handle animals may be misconstrued as abuse.

"I do think there's many in our agriculture community ... who do feel besieged," he said. "And they do feel like in today's urban world folks don't understand what standard agriculture practice looks like."

Hedy Weinberg, executive director of the American Civil Liberties Union of Tennessee, said the veto "is a victory for freedom of speech and freedom of the press in Tennessee."

"This legislation would have criminalized individuals, including journalists, seeking to document and expose animal cruelty, violating their First Amendment rights," she said.

Frank Gibson, public policy director of the Tennessee Press Association, agreed.

"If the bill had stood it would have impeded the work of news photographers and reporters and others seeking to document animal cruelty," Gibson said. "The veto shows that the process and our system of government work well when there is transparency and when someone in authority listens and considers all sides of an issue."< /P>

The Tennessee Farm Bureau, supporters of the bill, issued a statement saying the group is disappointed with Haslam's veto, but "we are appreciative of his recognition that well-established ... agricultural practices on farms are vulnerable to unfair attacks through misrepresentation and deception."

"For the farm community this bill was all about protecting animals by stopping abuse quickly and ending the exploitation for sensationalism," according to the statement. "Our farmers take the responsibility to care for animals very seriously. We will continue to be optimistic that we can care for animals and work to prevent animal cruelty."

The legislation easily passed the Senate, but gained just 50 votes in the House - the bare minimum needed to clear the chamber.

The bill's sponsors - Republican Sen. Dolores Gresham of Somerville and Rep. Andy Holt, R-Dresden - said in a joint statement that they respect Haslam's decision, but aren't giving up on the legi slation.

"We ... look forward to working with law enforcement officials, district attorneys, the agriculture industry, and the animal welfare community to craft a better and more legally enforceable bill to address animal abuse during next year's legislative session," they said.

The veto is Haslam's second since he took office in 2011.