With the shooting death Thursday of an FBI agent in New Jersey, 50 FBI agents have been killed while performing their duties.

The FBI categorizes these deaths between:

1. Killed in the line of duty.

"The FBI honors its Special Agents killed in the line of duty as the result of a direct adversarial force; or, at or by the hand of an adversary. The names of these Agents, who are appropriately termed "Service Martyrs," are included on a permanent plaque so that their ultimate sacrifice will always be remembered. The inscription on this Service Martyr Plaque reads: "In memory of Special Agents of the Federal Bureau of Investigation who were killed in the line of duty as the direct result of an adversarial action."

Fifteen agents, not including Thursday's fatality, have been honored for giving their lives in the performance of their law enforcement.

2. Killed during an adversarial confrontation.

Thirty-four agents were designated as "Service Martyrs" as of September, 2001.

"The FBI also honors those Agents who lose their lives in the performance of their duty, but not necessarily during an adversarial confrontation. This would include situations involving "hot pursuit" of criminals and when death results from the Agent taking immediate action to save one or more lives. A separate plaque memorializing the sacrifice of these Agents reads: "In memory of Special Agents of the Federal Bureau of Investigation who lost their lives in the performance of a law enforcement duty."

Official FBI Web site