For Kiefer Sutherland
, it's case closed on both coasts, no ifs, ands or headbutts.
"We declined to prosecute after a full investigation," Manhattan District Attorney spokeswoman Alicia Maxey Greene tells PEOPLE of the highly publicized alleged cranial collision
with a New York fashion designer in May. "That included speaking to the complaining witness, who was quite uncooperative."
Sutherland, 42, is also off the hook with the L.A. City Attorney's office, which investigated the actor for a possible probation violation. Sutherland is currently serving a five-year probation term following a second DUI conviction
"Based on the evidence and information received from New York officials, as well as our own independent review of the evidence, we will not be seeking a violation of Sutherland's probation," L.A. City Attorney spokesman Frank Mateljan says.
Sutherland's attorney, Blair Berk, declined to comment.
In May, the 24 star and his alleged victim Jack McCollough resolved their differences
, issuing a joint statement. "I am sorry about what happened that night and sincerely regret that Mr. McCollough was injured," Sutherland said. McCollough added: "I appreciate Mr. Sutherland's statement and wish him well."