"From all available information, these acts of violence were as random as they were savage," Craig Matheson, Snohomish County's chief criminal deputy prosecutor, wrote in court documents.
Talbott is being held in the Skagit County Community Justice Centre in custody. It wasn't clear if he has a lawyer.
Van Cuylenborg and Cook left their Saanich, British Columbia, homes for an overnight trip to Seattle to buy furnace parts for Cook's family business.
When they failed to return home, their families filed a missing persons report. Their bodies were found days later.
Van Cuylenborg had been sexually assaulted, bound with plastic ties and shot in the head. Investigators say the assault evidence provided a direct link to Talbott.
Cook's battered body was found about 120.7km away. Police say he was beaten with rocks and strangled.
Police say a genealogist used the DNA evidence and worked with a lab to build a family tree for the suspect.
Police say the genealogist used information uploaded by distant cousins to narrow their search to Talbott.
Police kept him under surveillance and finally got his DNA when a cup fell from his truck.
- AP