By David Ingram

NEW YORK (Reuters) - More than 100 U.S. police departments and law enforcement agencies will receive $20 million to help buy body cameras, the U.S. Justice Department said on Monday, in a bid to improve trust between officers and the public.

Demand for body cameras has risen amid a series of shootings of black men, many of them unarmed, by police, and last year the Obama administration unveiled a $20 million grant program.

The Justice Department on Monday announced how that money would be allocated. Funding was awarded to 106 state, city and tribal law enforcement agencies for equipment, training and evaluation.

The agencies are in 34 states and Puerto Rico, but a department spokesman did not immediately have a list of the agencies.

"Effective public safety requires more than arrests and prosecutions. It also requires winning - and keeping - the trust and confidence of the citizens we serve," U.S. Attorney General Loretta Lynch said in the statement.

On Monday, the American Civil Liberties Union of North Carolina called on police in Charlotte, North Carolina, to release all video footage and audio dispatch recordings relating to the fatal shooting of a black man last week.

Charlotte authorities on Saturday released two videos from the scene, after resisting several days of demands from demonstrators. The footage, however, failed to settle the question of whether the victim, Keith Scott, had been holding a gun at the time. [nL2N1C00A9]

Charlotte police did not immediately respond to a request for comment.

Lynch said the federal grant money would promote transparency and ensure accountability, although many state laws restrict the release of video recorded by police body cameras.

Eighteen states plus Washington, D.C., have laws governing public access to such footage, according to the National Conference of State Legislatures (NCSL). [nL2N1BY0IQ]

Five of those states treat body camera recordings as public record, but they also provide caveats allowing police to withhold, redact or obscure the video, the NCSL said.

Little research has been done on the value of police body cameras, according to a 2014 review by an Arizona State University criminologist.

There have been virtually no studies on whether cameras increase citizen views of police legitimacy, the review said. And while in some cases cameras were followed by fewer complaints against police, it was not clear if the decline was the result of improved officer behavior or another cause, it said.

(Reporting by David Ingram; Additional reporting by Colleen Jenkins in Winston-Salem, North Carolina; Editing by Cynthia Osterman and Lisa Shumaker)