Jeffrey Thompson, a Washington businessman who pleaded guilty on March 10 to funneling millions of dollars in illegal campaign contributions, got a “sweetheart deal” from prosecutors, criminal defense lawyers said.

Thompson faces a maximum sentence of six months in jail under the plea deal — far below the five-year maximum sentence under the law. If he cooperates in subsequent investigations, Thompson could serve no jail time: Prosecutors agreed to consider recommending a sentence at the low end of the guidelines, including probation or home detention.