Former state Treasurer Tim Cahill said the justice system worked after agreeing to a deal with the Attorney General's Office last week, but maintained he didn't think he did anything illegal.

'It's not an admission of guilt. It was an admission of perception of impropriety," Cahill said. "... I wouldn't admit guilt and I don't."

Cahill joined Emily Rooney on Greater Boston for his first broadcast interview since accepting a deal with the Attorney General's Office.

He said he didn't really contemplate prison, though it was in the back of his mind.

"It certainly would have ruined my life," he said. "Not just the time served, but the conviction alone would have ruined my life."

Cahill can't run for office until his probation is over, but said he wasn't planning on it any time soon anyway.

"If you ask Tina, never," he said.

As for former colleague Attorney General Martha Coakley, he's not holding a grudge.

"I don't hate anybody," he said. "She was doing what she thought she had to do."