New York board says officer used excessive force to arrest ex-tennis star James Blake

NEW YORK (Reuters) - One officer involved in the arrest of ex-tennis star James Blake, who was body-slammed outside a New York City hotel last month in a case of mistaken identity, used excessive force and another abused his authority, a police watchdog group has found.

The Civilian Complaint Review Board, in a letter to Blake dated Tuesday and obtained by Reuters on Thursday, said it had investigated and substantiated Blake's allegations that Officer James Frascatore used excessive force and Detective Daniel Herzog abused his authority by authorizing the bogus arrest on Sept. 9.

Blake, 35, who is black, was on his way to a corporate appearance at the U.S. Open when he was thrown to the ground and handcuffed by Frascatore, who is white.

The incident revived a debate over excessive police force against minorities that has reverberated around the country after a series of police killings of unarmed black men.

"I want to express my appreciation to the Civilian Complaint Review Board for their quick and thorough review of the incident during which I was attacked on September 9, 2015," Blake said in a statement.

Blake, who suffered cuts and bruises before he was released from custody within about 15 minutes, said he had "complete respect for the principle of due process."

Frascatore, who has been placed on modified assignment, has had five civilian complaints filed against him, according to media reports.

Mayor Bill de Blasio and Police Commissioner William Bratton have apologized to Blake. Ultimately, it will be up to Bratton to decide how the officers may be disciplined, according to the CCRB letter.

"Only the police commissioner has the authority to actually impose discipline against a police officer," the letter said.

Bratton told reporters on Thursday the case would now either move into a negotiated settlement between the officer and Blake, or to a trial before a judge employed by the police department.

Patrick Lynch, president of Patrolmen's Benevolent Association, the officers' union, called the CCRB "nothing more than a cop-hating branch of the New York Civil Liberties Union" and said the officers would be vindicated after an objective review of the facts.

Police have said Blake was mistakenly identified by "a cooperating witness" as being involved in selling fraudulently purchased cellphones.

(Reporting by Barbara Goldberg; Editing by Frank McGurty and Eric Beech)