Blood stains from the shirt of a man killed in a shootout with police last month helped authorities confirm the death of Ramon Arellano Felix, the suspected leader of Mexico's most feared drug gang and one of the FBI's 10 most-wanted fugitives. 

Assistant Attorney General Juan Jorge Campos said Mexican authorities compared blood taken from Arellano Felix's jailed brother, Benjamin, with DNA evidence collected from the shootout at the Pacific coast resort of Mazatlan on Feb. 10. 

Tests showed the samples had a "genetic affinity" that proved the dead man was Benjamin Arellano Felix's brother, Campos said at a news conference Wednesday. U.S. and Mexican officials already had said they were almost certain the dead man was the fugitive. 

U.S. and Mexican officials say the two brothers ran a Tijuana-based drug ring that smuggled tons of cocaine and marijuana into the United States and killed hundreds of people over the past 15 years. 

Other siblings have alleged roles in the organization, but authorities say the death of one brother and the arrest of the other may mean its demise. 

The FBI posted the 37-year-old Ramon Arellano Felix, accused of being the gang's enforcer, on its 10 most-wanted list in September 1997. A 1999 DEA report attributed about 300 murders in Mexico and the United States to the gang. 

U.S. and Mexican police agencies had determined that Arellano Felix came to Mazatlan on Feb. 5 with a plan to kill a rival during Carnival celebrations. Police say his death resulted from a chance encounter with traffic police who saw guns in the car he was driving. 

A day after the shootout, people who identified themselves as relatives of the slain man arrived and claimed the body from a funeral home, using false documents. 

On Saturday, Mexican troops captured Benjamin Arellano Felix in a raid on a house in Puebla, east of Mexico City. Authorities said police found an altar honoring Ramon's memory, and that Benjamin Arellano Felix told interrogators his brother was dead.