Federal authorities said a New York-bound plane was returned to Hawaii when an aggressive passenger threatened fellow travelers and crew members and said he was going to slit his girlfriend’s throat.

The passenger, James W. August, who was onboard Hawaiian Airlines Flight 50 on Tuesday, had allegedly been drinking alcohol and became belligerent, the FBI said.

The plane, which was headed to John. F. Kennedy International Airport in New York, was diverted to the Honolulu International Airport for the safety of those on board, according to a criminal complaint.

Neither an attorney for August nor Hawaiian Airlines could immediately be reached for comment.

Assistant U.S. Attorney Tom Brady told the Associated Press this week that it appeared that August, his girlfriend and her three children had been visiting Hawaii.

The FBI said that as the plane was boarding, August’s girlfriend and her children sat down a row behind him on the plane and would not move. The girlfriend’s 11-year-old son, who was crying, grabbed a flight attendant and said, “Can you please just keep him away from us?” according to the court records. The documents state that by the time the plane had started to taxi, August was unruly.

During the meal service, a teenage boy told the attendant that August had called the girlfriend a derogatory word and referred to her children as “piggies.” He then “made multiple life-threatening remarks, and threatened to slice [the girlfriend’s] throat,” according to the court documents.

A flight attendant asked August to move to a different area on the plane, but he told her “he wasn’t going anywhere” and to “carry on,” according to the documents.

When the attendant told him she was not leaving, authorities said, he allegedly slapped her shoulder. Two male flight attendants then escorted August from the area, but he kept threatening to go back to his seat and punch his girlfriend in the face, according to the court documents.

As August became more aggressive, the captain decided to turn the plane around and return to Honolulu. Upon landing, authorities boarded the plane and took him into custody, according to the documents.

The assistant U.S. attorney told the Associated Press that a federal judge released August to a halfway house Wednesday in Honolulu. August was ordered not to contact his girlfriend or her children, according to the news agency.

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