JEFFERSON CITY, Mo. (AP) — A man sentenced to life in prison without parole on a marijuana-related charge walked out of a Missouri prison a free man on Tuesday, after spending two decades behind bars.The release of Jeff Mizanskey followed years of lobbying from family, lawmakers and advocates for the legalization of marijuana, who argued that the sentence was too stiff.Mizanskey was sentenced in 1996 after police said he conspired to sell 6 pounds of marijuana to a dealer connected to Mexican drug cartels.