When a man ducked past security at Newark Liberty International Airport last Sunday to kiss his girlfriend goodbye, the breach in security shut down one of the country’s busiest airports, delayed flights through Monday and prompted an intensive manhunt from New Jersey detectives that ended on Friday evening on a street in Piscataway, N.J.

But the man police sought was not even home. He was at the gym.

When Haisong Jiang, a 28-year-old Rutgers University graduate student, returned, the police arrested him.

On Saturday, some of Mr. Jiang’s roommates described him as a “romantic” now trying to secure a lawyer after the dizzying turn of events. His actions might have seemed innocently romantic to him, his friends said. But the incident was yet another lapse in airport security that frustrated harried travelers in the wake of the failed plane bombing on Christmas and incensed one New Jersey lawmaker over the leniency of Mr. Jiang’s potential penalty.

Image 28-year-old Haisong Jiang, center, is led out of the Port Authority Police building at Newark Airport early Saturday. Credit... Joe Epstein/Associated Press

According to a statement from the Port Authority of New York and New Jersey, Mr. Jiang would be charged with defiant trespass. He was issued with a summons and told to appear in Newark Municipal Court.