The topic of drug criminalization cannot be avoided when discussing the Leary Papers; specifically, the laws governing marijuana. Although Leary is most closely associated with LSD-25 and other psychotropic drugs from his work at Harvard, the International Federation of Internal Freedom, Castalia Foundation and the League for Spiritual Discovery, the drugs centered in his research were not criminalized until after his first drug-related arrest.
The root of Leary's legal troubles stemmed from his arrest in 1965 while crossing the Mexican border with marijuana in Laredo, Texas. At this time, the Marijuana Tax Act of 1937 was on the books, penalizing the transfer and dealing of marijuana and hemp.
Leary's conviction was overturned by the US Supreme Court in 1969 when the Act was ruled unconstitutional. The court found that the Marijuana Tax Act violated the 5th amendment against self-incrimination, in Leary vs. the United States. Congress responded by passing the Controlled Substances Act in 1970, creating the currently enforced five classifications of substances based on their potential for abuse. Marijuana, fell under schedule I, along with LSD (aka acid), psilocybin (mushrooms), mescaline (peyote) and heroin.
Leary was arrested a second time in 1968 for marijuana possession after having his car searched in Laguna Beach, California. He began his sentence in 1970 at a low-security prison in San Luis Obispo. He escaped in September with the help of his wife, Rosemary (née Woodruff). This is when his life takes on even more dramatic turns. Reportedly, the Brotherhood of Eternal Love and the radical group the Weather Underground helped smuggle the Learys to Algeria, where they stayed with Eldridge Cleaver and others associated with the Black Panther Party.
Appeal for Swiss Asylum
By 1971, Leary and Rosemary left Algeria and eventually arrived in Switzerland, at which point the document, Declaration of Independence For Dr. Timothy Leary July 4, 1971: Model Statement in Defense of the Philosophers Personal Freedom was delivered to Swiss authorities on Bastille Day, July 14. Written by Allen Ginsberg and signed by other notable members of the San Francisco Bay Area Prose Poets' Phalanx, the statement outlined his legal problems and petitioned the Swiss government to grant him permanent exile on the following basis:
...That although this original conviction of Dr. Leary was overthrown by the U.S. Supreme Court, the Federal police bureaucracy in America indicated its continued hostility to his 'publicized activities' (namely, essays and speeches on drug usage theory) by trying him again for the same minor event, and by such abuse of language succeeded in having Dr. Leary sentenced to a 10-year jail term...
Whatever one's opinions, or natural or national preferences amongst intoxicants, Letters, religions, and political or ecological theory, the Bay Area Prose Poets' Phalanx hereby affirms that Dr. Leary must certainly have the right to publish his own theories... The case of Dr. Leary is outright a case of persecution of ideas and texts—the persecution of his philosophy. Though arrested for grass, he was sentenced for Philosophy. Jailed for grass, he was long prisoned for Opinion. Denied bail for grass possession, he was detained behind barbed wire for Ideological Heresy.
Timothy Leary, circa 1970-1973
On July 8th, a letter was sent to PEN Club President Thomas Fleming, Committee on Censorship and Prisons and the PEN Club Executive Board with the attached declaration requesting the adoption and submission of the statement to the International PEN Club before a final decision from the Swiss authorities was reached. The literary and human rights organization, International PEN, was founded in 1921 during the First World War, with branches throughout the world including the PEN American Center. Thomas Fleming showed his support, along with Arthur Miller, International Vice President, and David Dempsey, Chairman, Writers in Prison Committee, in a cable sent July 15th, from New York to the Swiss Ministry of Justice, Zurich.
An "Asylum of Leary Committee" was headed in Switzerland with branches in the States, England and Germany. The efforts of these committees inspired individuals to write letters of support to the Swiss government. The Swiss authorities did eventually imprison Timothy Leary. He was held at the Prison du Bois-Mermet in Lausanne and held briefly in solitary confinement. He was released August 1st., Swiss National Day. 
Timothy Leary continued to receive support from friends and the public for his perceived legal persecution. In 1973, Leary was apprehended in Afghanistan with his partner, Joanna Harcourt-Smith, and deported back to the United States where he served three more years in prison.
 Greenfield, Robert. Timothy Leary: A Biography. Orlando: Harcourt, Inc, 2006. 426-7.