Horton was a lecturer at Columbia Law School,[1][4] as well as a co-founder of the American University in Central Asia[8] and of Sanghata Global.
[10] He "served as counsel to Andrei Sakharov and Elena Bonner, among other activists in the former Soviet Union.
"[7] Horton was hired by the Associated Press to represent Bilal Hussein, a photojournalist who had won the Pulitzer Prize and was detained without charges by the US military for over a year.
[11] Horton has written blog posts on the Harper's Magazine website concerning the case of the Guantanamo Bay detention camp whistleblower Lieutenant Commander Matthew Diaz.
On August 28, 2009, Horton asserted that the treatment of Raymond Azar in Bagram Theater Internment Facility in April 2009 by Department of Justice officials was identical to the now-prohibited torture techniques that CIA snatch teams had once used on "high-value detainees" during the War on Terror.