Seattle police announced Monday that an arrest has been made in connection with a double homicide last month in Rainier Beach.

An 18-year-old man was arrested Sunday in Federal Way by Seattle police officers with help from U.S. Marshals and the Valley SWAT team, according to an update posted on the Seattle Police Department’s online blotter.

The suspect was booked into the King County Jail just after 8:30 p.m. on investigation of homicide and unlawful possession of a firearm, jail records show. He is to make his first court appearance Monday afternoon.

Around 6:20 p.m. on May 23, a large group of people had gathered in the parking lot of the Rainier Beach Safeway store in the 9200 block of Rainier Avenue South, police reported at the time. A disturbance broke out and shots were fired, causing the group to scatter; the two male victims were left behind, according to police.

Both men died en route to Harborview Medical Center, said police.

The King County Medical Examiner’s Office identified the victims as Christopher Wilson Jr., 35, and Christopher Roberts Jr., 23. Wilson died from a gunshot wound to the torso, and Roberts died from multiple gunshot wounds. Both deaths were ruled homicides.