Her attorney, Tonda Curry, said last month that she and prosecutors agreed to a deal capping Richardson’s sentence at 18 years. Prosecutors say Richardson faces life in prison for the charge to which she pleaded guilty.
A federal judge ultimately will sentence Richardson at a later sentencing hearing, which has not yet been scheduled.
“Shannon is anxious to admit her role in ordering the components to make the ricin, her role in the letters that contained the ricin, and to tell the government who else was involved in those offenses,” Curry said.
Curry did not say more about Richardson’s possible motives or whom she might name.