DENVER (AP) -- Police in some medical marijuana states who once routinely seized illegal pot plants by ripping them out by their roots and stashing them away in musty evidence rooms to die are now thinking twice about the practice.
From Colorado and Washington state to California and Hawaii, police are being sued by people who want their marijuana back after prosecutors chose not to charge them or they were acquitted.
In some cases, the one-time suspects are asking for hundreds of thousands of dollars to replace dead plants.
Concerns over liability have prompted some agencies to either forgo rounding-up the plants altogether or to improvise by collecting a few samples and photographing the rest to use as evidence for criminal charges.
"None of us really are sure what we're supposed to do, and so you err on the side of caution," said Mitch Barker, executive director of the Washington Association of Sheriffs and Police Chiefs.
The change comes as the notion of marijuana as medicine clashes with police seizure procedure that was developed in an era when pot was a scourge that needed to be wiped out.
"Law enforcement is going to have to think more carefully about what their procedures are and how those procedures might need to change in light of changes in the law," said Sam Kamin, a University of Denver law professor.
Just as the smell of pot smoke may no longer be grounds to search a home or make an arrest, Kamin, who helped craft the state's pot regulations, said, "the same evidence that two or three years ago would have given police probable cause today doesn't."
Most local police say they are seizing less weed post-legalization, but they still investigate if they suspect patients are growing more than they should. Federal agents face no such quandary since pot remains illegal under federal law.
Whether or not state laws require, as they do in Colorado, police to return medical marijuana intact if a suspect isn't charged or is acquitted, departments have been sued over pot that has wilted in their evidence lockers.
In Colorado Springs, a cancer patient who had faced drug charges is suing police after 55 dead plants were returned to him. The state appeals court had to order the police to return them.
Medical dispensary owner Alvida Hillery sued police to return her 604 pot plants or pay $3.3 million after she was acquitted of drug-cultivation charges. She dropped the suit in exchange for a city dispensary license. By then, the plants had died.
"We need uniform rules, and law enforcement would be wise to develop those rules otherwise they will continue to be sued," said Hillery's attorney, Sean McAllister, who is representing another dispensary owner in a similar suit in federal court.
City patrol officers must now call a narcotics detective for advice if they believe they are in the presence of illegal weed.
In Hawaii, a group of medical marijuana patients who were never arrested sued in May after police seized 52 plants in a raid. They want $5,000 for each plant if they've died.
In Oregon, a narcotics task force takes only the number of plants necessary to bring a patient back into compliance with the law, said Washington County Sheriff's Sgt. Chris Schweigert.
"Ten years ago, you had that many plants, you just went in there and ripped them all out. Now, you've got to ask a few questions," said Sgt. David Oswalt, who supervises the Grand Junction police evidence room.
Oswalt's department tells officers who believe the questionable weed is legal for medical purposes to take clippings and leave the plants behind. If not, they can seize plants by the bundle.
Leaving plants behind carries obvious risks, said Jim Gerhardt of the Colorado Drug Investigators Association.
"It would be like arresting a cocaine dealer and taking a minuscule amount of the cocaine as a sample and then leaving it there for them to be used or sold," he said. "It's a complicated, messy issue."
Washington state does not require police to return plants to acquitted patients. The state's medical marijuana law allows gardens of 45 plants or less, though it doesn't expressly prohibit having multiple gardens on a single property.
Seattle police destroy marijuana plants after seizing them, documenting the hauls with photographs or samples that can be presented at trial if necessary, said police spokeswoman Renee Witt.
This month, they seized more than 2,200 marijuana plants, but arrested no one, in a raid of a purported medical marijuana operation.
"My God, we would run out of space if we had to preserve it, water it, light it," Witt said.
Police in Lynnwood, Washington, no longer seize medical plants, said Angelea Madsen, who supervises the evidence unit.
Officials last year returned 202 dead plants seized from a group of medical marijuana patients who were never charged with crimes. They demanded police return the weed and growing equipment or pay nearly $1 million, the estimated value.
John Jackson, the police chief in Greenwood Village, Colorado, and a vice president of the state's association of police chiefs, said state lawmakers must enact guidelines on marijuana seizures to protect law enforcement from civil and criminal liability.
"There's no property room in the world that's going to turn into a hydroponic growing operation," Jackson said.