A survey of the largest cities in Colorado and Washington found that K-9 units' responses to legalization measures approved by voters last November vary as much as the breeds of dogs on their teams.
Some police departments won't use animals that were trained to smell marijuana, Fiorillo said, adding that Colorado Springs' K-9 unit will continue to use dogs like Vader based on advice from the local prosecutor.
A month ago, the Colorado District Attorneys' Council started traveling around the state to instruct police officers that a drug-sniffing dog reacting to the smell of marijuana isn't enough for probable cause, said Tom Raynes, the council's executive director.
"The issue is they could be hitting on a legal quantity," Raynes said.
In Washington, the state's Association of Prosecuting Attorneys wrote in a Dec. 4 memo that an officer seeking a search warrant based in part on a dog's alert must disclose the canine's previous training.
The memo, written by Pam Loginsky, the association's staff attorney, recommends that search warrants based in part on a canine trained to detect marijuana include when the dog was trained. She also suggested listing what odors it's trained to detect, that it "cannot communicate which of these substances s/he has detected" and that the dog "cannot communicate" the amount of the substance that's present.
The Washington State Patrol won't train new dogs on its canine team to sniff for marijuana, said Bob Calkins, a spokesman.
"In the past it used to be, if a dog alerted, that was probable cause for a search warrant," Calkins said. "Now, along with the dog's alert, we have to have an indication that there's reason to believe it's something other than marijuana."