The prosecutors had been looking into weather Bell's civil rights were violated when he was shot outside a Jamaica, Queens, strip club.
The officers - undercover detectives investigating reports of prostitution at the club - said they opened fire because they thought one of the men was reaching for a gun, firing 50 shots at Bell's car. No weapon was found.
After months of study, the prosecutors finally determined that they could not try the officers in federal court.
The family "will not stop our pursuit of justice in this matter until every measure in the criminal and civil arena has been exhausted," Rev. Al Sharpton said in a statement. "Fifty shots on an unarmed man who engaged in no crime is intolerable."
Four police officers were acquitted of manslaughter and other charges in 2008.
Bell's supporters had lobbied prosecutors to charge the shooters with violating Bell's civil rights.
