Clay Tepel knew there were risks to setting up a medical marijuana shop: it could lose money, be robbed or be raided by authorities.

Still, he wasn't expecting the phone call one August day when a voice said the police were outside and he needed to open up or they would bust down the door. His first thought that it was a joke turned to terror when he opened the door.

Heavily armed officers in helmets, bulletproof vests and, oddly enough, Bermuda shorts stormed his store, handcuffed him, disabled security cameras and seized his drugs before taking him to jail. When he asked why his shop was invaded, an officer responded, "We're closing them all down."

Those words could prove prescient after Los Angeles County District Attorney Steve Cooley said last week he wants to shutter clinics that sell pot for profit. Cooley's plan is the latest salvo in a prolonged conflict in California over whether medical marijuana is truly having its intended effect or is being abused by the larger population.

Until recently, raids on clinics typically led to federal prosecutions, but Cooley's remarks and similar ones from Attorney General Jerry Brown signal a new approach to clear the haze left by Proposition 215, the 1996 state ballot measure that allowed sick people with referrals from doctors and an identification card to smoke pot.

"Everybody is scared," said Tepel, who has spoken with other pot store operators. "Why are voters' rights being stepped all over? This kind of blind justice has to stop."

The crackdown is a crushing blow for dispensary owners who were relieved in March when U.S. Attorney General Eric Holder said federal agents would only target marijuana distributors who violate both federal and state laws.

A three-page memo spelling out the policy is expected to be sent Monday to federal prosecutors in 14 states, and also to top officials at the FBI and Drug Enforcement Administration. Under federal law, marijuana is illegal.

The comments Holder made earlier this year appear to have emboldened entrepreneurs as marijuana shops cropped up across California. In Los Angeles alone, there are an estimated 800 dispensaries, more than any other city in the nation. In 2005, there were only four, authorities said.

Cooley contends a vast majority of several hundred outlets his office investigated aren't following state law. Initially, the law allowed authorized marijuana users to grow their own plants, but lawmakers revised the law in 2003 to allow collectives to provide pot grown by members.

Cooley said he would target stores who are profiting and selling to people who don't qualify for medicinal marijuana.

"All those who are operating illegally, our advice to them is to shut down voluntarily and they won't be subject to prosecution," Cooley told The Associated Press on Wednesday.

At the same time, advocates are gathering signatures to get as many as three pot-legalization measures on next year's ballot in California. One poll shows voters would support legalizing marijuana outright. Thirteen states, including California, allow medical marijuana.

Cooley said his office has been assessing the rush of marijuana dispensaries for the past two years and has provided training for his staff over the past several months in anticipation of filing cases.

"Holder's statement probably created the impression that there wasn't going to be any federal investigation or prosecution of these entities," Cooley said. "There has to be some clarification."

Some legal observers believe the first case Cooley files since his announcement will show how egregious the illegal behavior has become among medical marijuana outlets.

"He's going to find a dispensary that is way over the line," said Rory Little, a professor at the University of California Hastings College of Law.

Among the candidates are Jeffrey Joseph, who runs Organica and was arrested in August but has yet to be charged. Authorities recovered 452 marijuana plants, more than 100 pounds of hashish and more than $100,000 in cash from his home and dispensaries in Marina del Rey and Culver City.

Defense attorney William Kroger said authorities fail to account for expenses and other costs dispensary owners incur and the proliferation of new rivals has hurt business.

"Most of my clients aren't making a lot of money," said Kroger, who represents about a dozen other owners. "I'd like to see Cooley sit down with us and keep shops open for those who need it and thin out the herd so there aren't so many of them."

James Shaw of the Union of Medical Marijuana Patients, an advocacy group for users, said his group plans to file a lawsuit against the city and county of Los Angeles to prohibit prosecution of legal organizations.

While the definition of a compliant dispensary is open to interpretation, Shaw said it's up to local municipalities to determine what matches up best with state law.

"Wherever there are regulations, there is less need for law enforcement intervention," Shaw said.

Nowhere is the topic more muddled than in Los Angeles, where city officials say plenty of people are getting high for the wrong reasons.

While the city has had a moratorium prohibiting new medical marijuana facilities for two years, officials have been unable to pass an ordinance governing the dispensaries. More than 180 dispensaries qualified to remain open under the moratorium, but many others took advantage of a loophole known as a "hardship exemption" that allowed them to open while awaiting city approval.

Tepel, a married father of four, agrees some pot clinics abuse the system but he maintains he had all the proper paperwork and followed the rules. If police had thoroughly investigated, they would have found most of his customers were either older or female, as opposed to younger men, and many grew their own marijuana and sold the drug to Tepel as allowed by the state.

After investing tens of thousands of dollars, Tepel argued it will take years to recoup his investment.

Tepel believes his shop in a strip mall with tinted black windows was targeted because it was on a busy street and not "in the hood or in a back alley."

"We're not tatted-up drug dealers. This is a family run operation," said Tepel, who is scheduled to be arraigned Monday on one count of felony possession of marijuana with the intent to sell. "I don't want to do anything to jeopardize my future, my family's future. We didn't deserve this."