A man is suspected of assaulting a traveler in what police are calling an unprovoked attack Saturday at Salt Lake City International Airport, where he managed to enter a concourse despite having no ticket.

According to arrest documents, the victim reported that the man, 42, went into Concourse G and began punching him “for no reason.” The man then took the victim’s cellphone and walked away, police wrote.

He was booked into jail on suspicion of robbery and assault.

The man did pass through a security screening, despite not having a ticket for a flight, the TSA confirmed on Monday.

"TSA’s travel document verification procedures were not properly followed at Salt Lake City International Airport on Saturday, March 30," TSA officials wrote in a prepared statement. "As a result, an individual who was not ticketed for travel gained access to the sterile area of the airport. The individual and his belongings were screened through the security checkpoint with no alarms. TSA will cooperate with law enforcement in its ongoing investigation.”

Neither the TSA nor police have disclosed how the man passed through checks for travelers’ tickets and ID at the security screening. Several witnesses and video footage corroborated the victim’s account, police wrote.