NORMAN, Okla. — An Oklahoma prosecutor dropped drug-related charges Monday against the owner of a now-closed pipe shop in Norman and a store clerk after previous trials on similar charges ended in acquittals and a hung jury.

Online court records indicate charges were dismissed against Robert Cox, who owned Friendly Market, and former clerk James Maxwell Walters.

The dismissal comes after Cox and manager Stephen Holman, who’s also a Norman city councilman, were acquitted in May on several charges, including a felony charge of acquiring proceeds from drug activity. The trials of two other clerks ended in a hung jury and an acquittal.

Defense attorney Brecken A. Wagner of McAlester, Oklahoma, who represented Cox and Holman in the case, said dismissal of the charges was unexpected.

“It is a surprise to me,” Wagner said. “We thought they might do that after the first trial. We thought they might do it after the second trial. We thought they might do it after the third trial.”

He said Cox, Holman and the others charged in the case faced the possibility of criminal convictions and penalties by refusing plea deals and insisting on a trial and that dismissal of the remaining charges “says that I represent some of the most courageous people around.”

In a statement, Cleveland County District Attorney Greg Mashburn said he plans to prosecute similar cases but that evidence in the pending cases wasn’t substantially different than what had already been presented to juries.

Mashburn said he will work with law enforcement agencies to successfully prosecute similar cases in the future.

The charges followed a series of undercover sting operations and police raids on the store that sold a variety of items like tapestries, jewelry, locally made art and glass pipes.

Authorities alleged the pipes fit the state’s definition of drug paraphernalia, but Cox maintained all of the items can be used to smoke tobacco and are therefore legal under state law.

Mashburn said he believes police and prosecutors need to be proactive about the issue of drug paraphernalia.

“By taking paraphernalia off the streets, I believe we can help deter illegal drug use,” Mashburn said. “Less illegal drug use means a safer community.”