BOSTON — More than 16 years after he fled Boston, former crime boss James “Whitey” Bulger pleaded not guilty Wednesday to participating in 19 murders and committing a host of other crimes dating back to the 1970s.

Bulger said “not guilty” in a subdued but clear voice during his arraignment on the 32-count racketeering indictment as his two brothers, John Bulger and former Massachusettse Senate President William Bulger, watched from the front row.

Bulger, a former top-echelon FBI informant, fled in late 1994 after receiving a tip from his FBI handler that he was about to be charged in another case that has since been dismissed.

Now 81, Bulger escaped prosecution until he was captured last month in Santa Monica, Calif.

The courtroom Wednesday was packed with spectators, reporters, family members of Bulger’s alleged victims and a who’s who of law enforcement officials who investigated Bulger during his decades as the reputed leader of the notorious Winter Hill gang.