The former mayor of the eastern Iowa town of Wilton has pleaded guilty to a federal charge of conspiracy to deliver marijuana.

Dick Summy was charged last September with distributing and manufacturing about 100 marijuana plants. He entered his plea Tuesday in U.S. District Court in Davenport, but the judge said he'll take a few days to decide whether to accept the plea.

At issue is a law that prohibits someone from being prosecuted for the same crime twice.

The prosecutor is concerned that because Summy pleaded guilty to conspiracy to deliver a controlled substance, he could not be tried for conspiracy to manufacture.

Summy's attorney said Summy believes he conspired to distribute marijuana but did not conspire to manufacture the drug.