Seattle Police arrested 30-year-old Musab Mohamed Masmari Saturday morning in connection with the arson at Neighbours nightclub on January 1.
Police took Masmari into custody as he was en route to the airport.
Police say following the arrest, Masmari was interviewed by detectives and later booked into the King County Jail for Investigation of Arson.
It was just after midnight on New Year's Eve while nearly 700 people crammed into Neighbours for a celebration when customers noticed the staircase at the iconic gay club was on fire.
Management at the iconic gay club in Capitol Hill later discovered a gasoline container near the stairs.
No one was injured.
Neighbours released surveillance video that police believe shows Masmari as he walks into the club.
The video was captured around the time of the countdown to midnight on New Year's Eve. Masmari is carrying something in his hand.
The bar later found a container of gasoline at the top of a staircase. According to SPD, Masmari doused the staircase with fuel and set it on fire.
Detectives worked on the case with the Joint Terrorism Task Force.
A woman who lived next door to Masmari for three years calls him erratic and violent.
“We’re scared of him,” she said. “He yells and throws things.”