Stephen M. Misko is not denying that James R. Sed was involved in a drug deal when he was arrested April 27, 2006.

But, Misko said, the arrest had two flaws that should kill the prosecution of Sed.

Not surprisingly, prosecutors believe police worked within the boundaries of the law and have asked a judge not to suppress evidence of the arrest and all evidence collected after it, including a confession by Sed, or throw out one of the charges.

Sed, 48, of 890 Hasenflu Drive, Hermitage, has been indicted by a federal grand jury on charges of conspiracy to distribute and possess with the intent to distribute 50 grams or more of crack, distribution and possession with intent to distribute 5 grams or more of crack and attempted distribution and possession with intent to distribute 50 grams or more of crack.

Sed, who has pleaded not guilty and is free on bond, was the go-between in two drug transactions, law enforcement officials said.

He made arrangements with an informant working with Sharon and state police in which 2 ounces of crack was sold April 21, 2006, for $2,400 to the informant, officials said. The drug was provided by Mark A. Grannison, 48, of 290 Orchard St., Sharon, who pleaded guilty in July to conspiracy and possession with intent to distribute 50 grams or more of crack. Grannison is free on bond and no sentencing date has been set.

Sed’s fiancée, Stacie M. Hickman, 38, of 2095 Mary St., Hermitage, accompanied Sed, officials said. She pleaded guilty to conspiracy in September. She is free on bond, and her sentencing also is pending.

Misko’s motion deals with the events of April 27, 2006, when police set up a buy of 5 ounces of crack for $5,350, officials said. Sed and Grannison were arrested when Sed entered Grannison’s vehicle, apparently to get the crack, and Ms. Hickman was arrested a short distance away. Ms. Hickman had $180 of the buy money on her, Grannison had money on his lap, and 5 ounces of crack was found in the back seat, officials said.

At a hearing In March, state police troopers testified that an undercover trooper gave the money to Sed and Ms. Hickman on South Irvine Avenue in Sharon, and the couple drove into the parking lot of Standard Market on Route 62, Masury, to turn over the money to Grannison and get the cocaine, prosecutors said.

Grannison drove into Sharon, circled the undercover trooper, then headed back to Sed and Ms. Hickman. Sed got into Grannison’s car, and a state police supervisor ordered the “take down” when he believed the car had entered Sharon.

The supervisor, Cpl. Timothy P. Wiles, said he later came to believe the arrest occurred in Ohio.

In an argument brief, Misko said state troopers violated Sed’s constitutional protection against unreasonable searches and seizures by arresting in Ohio, outside their jurisdiction.

Sed’s arrest also was illegal because he, as a passenger in the car, had an expectation of privacy, Misko said.

“Defendant Sed was a business invitee in Grannison’s vehicle for the purpose of conducting drug-related transaction as the direction of the undercover officer,” Misko said.

Assistant U.S. Attorney Troy Rivetti said in his brief that the Supreme Court recently supported an arrest similar to Sed’s. Police are allowed to arrest someone when they believe they have seen that person commit a crime, and to search the suspect to obtain evidence and ensure their own safety, the court said.