A man and woman have been accused of murdering a 74-year-old Washington state man who disappeared last month, as part of a wider financial fraud scheme, authorities said. The pair were arrested on Thursday in Southern California and will be extradited back to Washington to face homicide charges.

Curtis Engeland’s family reported him missing on Feb. 24, one day after authorities said he was last seen at his home on Mercer Island, in southern Lake Washington near Seattle, police said in a statement. 

Although police originally investigated the disappearance as a missing persons case potentially involving a kidnapping, they later found the man dead near Cosmopolis, a city some 100 miles west along the Pacific Coast. 

Police said Engeland was stabbed in the neck, CBS affiliate KIRO-TV News reported.

Investigators used GPS information from the suspects’ cell phones to find Engeland’s body, according to Mercer Island police. They said the probe so far suggests that the suspects became acquainted with Engeland several months before his death and financially defrauded him. Police believe that the suspects “violently confronted” Engeland at his home on Mercer Island on the evening of Feb. 23 and used his car to leave the area that same night. 

Police have not shared more details about the circumstances surrounding that confrontation, but Mercer Island police said that detectives believe both suspects left Washington state soon after Engeland was killed. They alleged the suspects then rented new vehicles and changed cell phones “to cover their path.”

The suspects were identified as 32-year-old Philip Brewer and 47-year-old Christina Hardy, KIRO News Radio reported, citing police as well as charging documents filed by the King County Prosecuting Attorney’s Office. 

Prosecutors said that Brewer and Hardy “appear to have concocted a scheme to kill the victim and then move into his home, all while taking over his financial accounts and making extravagant purchases just hours after killing him,” according to KIRO News Radio. They also alleged the suspects used Engeland’s cell phone, after his murder, to conduct falsified conversations between them in an ostensible attempt to dupe authorities into thinking he was still alive.

CBS News contacted the Mercer Island Police Department for more details but did not receive an immediate reply.