Gezmiş became increasingly politically active, established the Revolutionary Jurists Association in January 1966[7] and was involved into the student-organised occupation of Istanbul University in June 1968.

[6] After the occupation was forcibly subdued, he spearheaded protests against the arrival of the US 6th Fleet in Istanbul,[8] when several US soldiers were harmed and pushed into the sea on 17 July 1968.

As he increased his involvement with the Worker's Party of Turkey, and began to advocate for a National Democratic Revolution, his ideas started to circulate and inspire a growing revolutionary student base.

Gezmiş was re-arrested after leading Istanbul University Law Faculty students on a protest of the reformation bill[clarification needed] on 31 May 1969.

[10] In 1969, Gezmiş led a group of students who "violently disrupted" a lecture American scholar Daniel Lerner was to give at Istanbul University.

[13] On 4 March 1971, he and other members of the People's Liberation Army of Turkey (THKO) kidnapped four U.S. privates[14] from the TUSLOG/The United States Logistics Group headquartered in Balgat, Ankara.

Three young men delivered a news agency a note confirming the authorship of the THKO together with an ID or a relative of a soldier, demanding a ransom for the US soldiers by 6 p.m.[15] Since a driver of the THKO was captured, a second note delivered to a Turkish news agency prolonged the deadline by 12 hours, this time demanding the release of the driver.

[15] After releasing the hostages, he and Yusuf Aslan were captured alive in Gemerek, Sivas[16] following an armed stand-off with law enforcement officers[17] Following Gezmiş was brought to Ankara and presented to the Turkish minister Haldun Menteşoğlu and the public.

[19] Gezmiş, Yusuf Aslan and İnan were sentenced to death on 9 October[20] for violating the Turkish Criminal Code's 146th article, which concerns attempts to "overthrow Constitutional order".

[22][19] Other actions to overturn the verdict were manifestations in front of the Grand National Assembly of Turkey and a signature campaign initiated by Yasar Kamal and other Turkish intellectuals.