The four marijuana dispensaries raided by federal authorities in Washington state this week were all targets of previous federal raids.

Seattle Cross, Tacoma Cross, Key Peninsula Cross and Bayside Collective — formerly Lacey Cross — were among about 20 medical marijuana storefronts raided by the Drug Enforcement Administration in November 2011.

The DEA has provided little information about the four searches conducted Wednesday, but an employee at Bayside Collective told The Associated Press she was informed by agents that the raids were part of a two-year investigation.

A search warrant affidavit filed in support of the earlier searches said there was evidence that the medical dispensaries were fronts for commercial drug dealing. No federal criminal charges immediately resulted from the 2011 searches of those four shops.

Washington voters legalized adult possession of marijuana last fall, but it remains illegal under federal law. The state's medical marijuana law does not allow for storefront dispensaries, but many have been tolerated by law enforcement.