Updated

A Mississippi man who pleaded guilty to making ricin and sending letters laced with the poison to President Barack Obama and other officials now wants to withdraw the plea.

James Everett Dutschke (DUHS'-kee) pleaded guilty in January to sending the tainted letters to Obama as well as Republican U.S. Sen. Roger Wicker and Mississippi judge Sadie Holland. He was to be sentenced Tuesday in Aberdeen, Mississippi.

At the sentencing, Dutschke told U.S. District Judge Sharion Aycock that he was innocent and wanted a chance to prove it.

Aycock did not rule immediately. Aycock said she would look at arguments from the defense and prosecution.

"Your filing the motion to withdraw does not necessarily mean the court will grant it," Aycock told Dutschke. "I do want you to understand that your withdrawal is in the discretion of the court."

She said she will likely hold a hearing before ruling on Dutschke's request.

Dutschke argued FBI agents and federal prosecutors committed perjury, specifically regarding his DNA allegedly found on a dust mask.

Chad Lamar, the chief federal prosecution in the case, said there was not perjury.

"The defendant is simply mistaken," Lamar told Aycock. "The mask he threw in the coffee grinder box was the mask that tested positive."

Dutschke said he was making a harmless organic fertilizer not poisonous ricin.

He was so confident that the substance was harmless that he offered prosecutors a "free shot" by letting him eat the remaining substance that's in evidence.

"I will dump the contents of the two remaining letters on a peanut and butter sandwich and eat it and wash it down with a glass of chocolate milk," Dutschke said.