DULUTH, Minn. -

The owner of a Duluth head shop is asking the court to dismiss several federal charges relating to accusations he was selling synthetic drugs.

Attorney Randall Tigue told the Duluth News Tribune he filed a motion Friday to dismiss the charges dealing with controlled substances against his client Jim Carlson.

Carlson is the owner of Last Place on Earth. He and three workers have pleaded not guilty to federal charges of selling synthetic drugs. Authorities said they were misbranded and marketed as incense, potpourri or bath salts.

Tigue also filed a motion to suppress all evidence obtained in two search warrants served on the store.

He said he plans to eventually file motions to dismiss all 54 charges against Carlson, of Superior, Wis., before a June 20 hearing.