KEY PENINSULA, Wash. — Authorities in Washington state say a man and woman have been killed in a shooting that may have a drug connection.

The Pierce County Sheriff’s Department said on Facebook that deputies responding to a 911 call about a shooting at a mobile home in the Key Peninsula early Saturday arrested a suspect who was walking in the area.

Deputies got to the home and found a 35-year-old man and a 25-year-old woman dead in the driveway. The victims’ 2-year-old son was in the back of a vehicle during the shooting but wasn’t injured.

Authorities say the 27-year-old suspect and the victims were arguing, possibly about a recent domestic violence assault involving the suspect. The sheriff’s department says drugs are a possible factor.

The man accused of the killings was booked into jail on suspicion of murder.