The King County sheriff's office says detectives flew to Los Angeles and on Wednesday arrested Trayvon Cail with help from local authorities.
Cail was charged Thursday with first-degree murder, attempted first-degree murder and robbery.
A spokesman for the prosecutor's office said Friday that Cail remained in custody in Los Angeles. Bail has been set at $2 million.
Prosecutors say Cail fatally shot David Fashaw in the head and wounded Jermaine Smith on March 11. They say Cail stole a large sum of money from his victims.
About 50 marijuana plants were inside the apartment, according to King County sheriff's Sgt. Cindi West.