Mayor Vincent Gray has laid out his defense in the investigation of corruption in his mayoral campaign: He was clueless.

“I really thought, from my perspective, that we had raised a substantial sum of money,” he said Wednesday. On Tuesday, his former consultant, Jeanne Clarke Harris, had pleaded guilty to running an operation in 2010 that raised $653,000 in unreported campaign funds from a single businessman. “I don’t think any candidate can say, ‘I’m going to sit down and review with everybody every check that you give me.’ It’s just not possible.”