Mark William Cappello, 46, was arrested on Valentine's Day at 3 p.m. in Mobile, Ala., by the Mobile County Sheriff's Office.
On Feb. 5, the men were found dead in a cabin. They were waiting for someone who was going to sell them marijuana, a Sonoma County sheriff's lieutenant said.
"People associated with the victims said it was a pot deal gone bad. We believe the victims were associated with another involved party. The victims were the buyers," Lt. Dennis O'Leary said.
The sheriff's office has identified the victims as Richard Lewin, 46, of Huntington, N.Y., Raleigh Butler, 26, a former Petaluma resident who most recently was living in the Lake Tahoe area, and Todd Klarkowski, 42, of Boulder, Colo.
Butler's brother and Butler's brother's girlfriend, who called 911, found the bodies in the bedroom of a cabin on a property at 9707 Ross Station Road, O'Leary said. He said it's believed the shootings happened around noon.
Butler's brother told investigators he was expecting a call from his brother and became concerned and went to the home when he did not hear from him for four to six hours, O'Leary said. Butler's mother was renting a home on the property but was out of state when the murders occurred.
Sonoma County sheriff's detectives have been in Colorado for the past week collecting evidence and conducting interviews.
Cappello, who is a resident of Central City, Colo., is expected to be transferred to the Sonoma County jail.
The Sonoma County Sheriff's Office is asking anyone with information related to this investigation to call (707) 565-2185.