Norberto Gonzalez Claudio, a senior figure in the Boricua Popular Army, better known as Los Macheteros (Cane-cutters), was apprehended by FBI agents and Puerto Rican police in the central town of Cayey.
"After 25 years, eight months and eight days, the United States law and order agencies caught up with Norberto Gonzalez Claudio," FBI Special Agent in Charge Luis Fraticelli told a press conference in San Juan.
Gonzalez Claudio was wanted for the Sept. 12, 1983, armed robbery of a Wells Fargo armored-car depot in West Hartford, Connecticut.
The 16 other people indicted for the crime include two brothers of Norberto: Orlando Gonzalez Claudio, who served 16 months in prison in the mid-1980s; and Avelino Gonzalez Claudio, arrested in 2008 after living more than two decades under a false identity.
Though no one was hurt in the heist, prosecutors deemed it an act of terrorism because the $7 million stolen was destined for Los Macheteros.
Only one of those accused in the robbery remains at large, Fraticelli said Tuesday, indicating that fugitive Victor Manuel Gerena is thought to be in Cuba.
Norberto Gonzalez Claudio was alone when the FBI agents and police arrived at his home and did not offer any resistance, Fraticelli said.
The 65-year-old could be sentenced to 275 years in prison if convicted on all counts.
Los Macheteros founder Filiberto Ojeda Rios was killed in Puerto Rico in September 2005 when the FBI tried to arrest him in connection with the 1983 robbery in Connecticut.
Convicted in absentia for the crime and sentenced to 55 years in prison, Ojeda Rios had been on the run since 1990.
The 72-year-old fugitive died in a confrontation with FBI agents at a farmhouse in the western town of Hormigueros.
While few in Puerto Rico support the cause of independence from the United States, many on the island were upset about the way Ojeda Rios died, and the commonwealth's government unsuccessfully sued the FBI to obtain documents related to the fugitive's death.