Ravil Gumarov is a Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n citizen who is alleged to have ties to terrorism

Terrorism

Terrorism is the systematic use of terror, especially as a means of coercion. In the international community, however, terrorism has no universally agreed, legally binding, criminal law definition...

.

Gumarov was one of eight Russians held by the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 in extrajudicial detention

Extrajudicial detention

Arbitrary or extrajudicial detention is the detention of individuals by a state, without ever laying formal charges against them.Although it has a long history of legitimate use in wartime , detention without charge, sometimes in secret, has been one of the hallmarks of totalitarian states...

 in the Guantanamo Bay detention camps, in Cuba

Cuba

The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

.
His Guantanamo Internment Serial Number was 203.
The Department of Defense

United States Department of Defense

The United States Department of Defense is the U.S...

 reports Gumaraov was born on November 22, 1962, in Gushva, Russia

He was repatriated to Russian custody, cleared, then released.

He was subsequently rearrested for suspicion of an act of sabotage. Gumarov, fellow Guantanamo detainee Timur Ishmuratov

Timur Ishmuratov

Timur Ishmuratov is a Russian citizen who was held in extrajudicial detention in the United States Guantanamo Bay detainment camps, in Cuba.Ishmuratov was one of eight Russians held by the United States in extrajudicial detention in the Guantanamo Bay detainment camps, in Cuba...

and Fanis Shaikhutdinov

Fanis Shaikhutdinov

Fanis Shaikhutdinov is a Russian citizen who was convicted of bombing a natural gas pipeline, together with two former Guantanamo detainees, Ravil Gumarov and Timur Ishmuratov, guilty.-References:...

 were convicted of bombing a natural gas pipeline on May 9, 2006.
Gumarov has been described as a failed businessman from Sverdlovsk

Yekaterinburg

Yekaterinburg is a major city in the central part of Russia, the administrative center of Sverdlovsk Oblast. Situated on the eastern side of the Ural mountain range, it is the main industrial and cultural center of the Urals Federal District with a population of 1,350,136 , making it Russia's...

 who is alleged to have had military training in Chechnya

Chechnya

The Chechen Republic , commonly referred to as Chechnya , also spelled Chechnia or Chechenia, sometimes referred to as Ichkeria , is a federal subject of Russia . It is located in the southeastern part of Europe in the Northern Caucasus mountains. The capital of the republic is the city of Grozny...

.

Defense Intelligence Agency claims he "returned to terrorism"

The Defense Intelligence Agency

Defense Intelligence Agency

The Defense Intelligence Agency is a member of the Intelligence Community of the United States, and is the central producer and manager of military intelligence for the United States Department of Defense, employing over 16,500 U.S. military and civilian employees worldwide...

 asserted Ravil Shafeyavich Gumarov had "returned to terrorism".
The DIA reported:

Ravil Shafeyavich Gumarov and Timur Ravilich Ishmurat were transferred to Russia in March 2004 and quickly released. Russian authorities arrested them in January 2005 for involvement in a gas line bombing. In May 2006 a Russian court convicted both, sentencing Gumarov to 13 years in prison and Ishmurat to 11 years.