When a group of thugs paralyze his friend, Eastland becomes a vigilante, embarking on a mission to cleanse New York of organized crime.

During a firefight in Vietnam, U.S. soldiers John Eastland and his best friend, Michael Jefferson, are captured by the Viet Cong.

One day, Eastland catches a group of thugs, called the Ghetto Ghouls, trying to steal beer.

Detective James Dalton begins investigating the attacks, while the press dub Eastland the "Exterminator".

Based on the current administration's promise to cut down crime rates, they believe the Exterminator is either an opposition party's stunt, or a foreign power's ruse to humiliate the current administration; by exposing their inability to handle the city's crime problem.

Dalton, working from a bootprint found at Pontivini's home, discovers the Exterminator wears hunting boots manufactured by a mail order firm in Maine.

Asking them for a list of clients in New York, and following the hunch that the Exterminator may be a Vietnam War veteran; since he killed the Ghetto Ghouls with an M16 rifle, Dalton has narrowed his suspects accordingly.

Eastland is aware that Dalton is staking out his apartment, so he arranges a private meeting with him, where he hopes to explain why he became a vigilante.

[6] The websites Letterboxd, Yardbarker, The Grindhouse Database and The Spinning Image list this movie as belonging to the vetsploitation subgenre.

At an advance screening, six months before the film's release, Roger Ebert, of the Chicago Sun-Times, criticized The Exterminator for being a "sick example of the almost unbelievable descent" that American movies had taken "into gruesome savagery".

Even though he found the opening scene quite "shocking", the acting a bit "ropey", and the effects "dated", he admitted the film "grabs you from the start".

He stated that while Ginty is "not the greatest or most charismatic" of actors, "his essential ordinariness really works within the confines" of the film.

Dr. Sharon Packer and Jody Pennington spoke of this controversy and the film's "extreme justice" in their book A History of Evil in Popular Culture.