Federal drug agents launched a wide-ranging crackdown on medical marijuana providers Wednesday, charging a husband and wife in Sacramento and raiding more than 20 San Francisco dispensaries.

In San Francisco, drug agents conducted searches of three pot clubs and more than 20 homes and businesses, capping a more than two-year investigation into an alleged marijuana trafficking ring.

Officials with the Drug Enforcement Administration and U.S. attorney's office would not say how many people were arrested or give other details, pending a news conference Thursday.

In Sacramento, Dr. Marion Fry, 48, and her husband, attorney Dale C. Schafer, 50, were arrested on a sealed indictment handed down a week ago. It charged them with conspiracy to grow and distribute marijuana between August 1999 and September 2001 from their storefront California Medical Research Center in Cool, a Sierra foothill community northeast of Sacramento.

"Marijuana was legal in this part of the United States until this month, so any attempt to hold them as serious criminals would have been, I think, inappropriate," said their attorney, Laurence Lichter. "They are charged with violating the old marijuana laws, which are now back in effect, and I'm hoping that the jury will see ... that Dr. Fry was acting as a physician."

Law enforcement officials in Sacramento and San Francisco said the actions were unrelated and were part of independent, long-running investigations.

Lichter, however, said he believed Wednesday's arrests and sweep may have been prompted by the U.S. Supreme Court's medical marijuana ruling two weeks ago. The high court said federal law prohibiting the sale and distribution of narcotics supersedes state medical marijuana laws.

First Assistant U.S. Attorney Lawrence Brown in Sacramento said the Supreme Court ruling "lays to rest any question whether federal authorities have jurisdiction."

California is one of 10 states that allow the use of marijuana for medicinal purposes.

State Attorney General Bill Lockyer supports the state's medical marijuana law, but his Bureau of Narcotics Enforcement was involved in the San Francisco investigation, spokeswoman Teresa Schilling said.

"It's more than medical marijuana. This was an illegal marijuana operation," she said.

Gordon Taylor, the assistant special agent in charge of the Sacramento DEA office, alleged that Fry and Schafer also crossed that line. The indictment states the couple was growing more than 100 plants during the period in question.

"They were taking their (medical) clients and turning them into their customer base" for illegal marijuana sales, Taylor said.

Both were freed without posting bond after an initial court hearing Wednesday.

That investigation has been pending since December 2000, when drug agents said they seized several United Parcel Service packages containing marijuana.

In September 2001, the DEA seized 28 filing cabinets full of patient records from the Medical Research Center, which doubled as Fry's doctor's office. That raid triggered a legal battle over patient privacy.

The DEA ended Fry's registration to dispense controlled substances in December 2002 based on the investigation, but no charges were filed until the indictments last week.