Jones never spent any time in prison. He spent a few hours in jail after a protest in San Francisco. He filed a lawsuit about that on behalf of himself and the others who were arrested and won a small settlement.
http://gatewaypundit.blogspot.com/2009/08/surprise-obamas-radical-green-czar.html
“In 1992, during the Rodney King riots in Los Angeles, Jones was arrested and jailed for his role in the protest. He said of his time in prison, “I met all these young radical people of color – I mean really radical: communists and anarchists. And it was, like, ‘This is what I need to be a part of.’ I spent the next ten years of my life working with a lot of those people I met in jail, trying to be a revolutionary...”