|Pathology|| Serial killer|
|Family|| Unnamed mother (deceased)|
Mary Bradley (née Tunney; sister)
Allen Bradley (brother-in-law)
Arthur Tunney was a white supremacist serial killer who shot four African-Americans living in his neighborhood.
Tunney developed white supremacist beliefs after his mother was killed by an African-American mugger. He projected blame onto the entire black race for her death and began subscribing to white power magazines. Tunney began prowling around his predominately African-American neighborhood armed with a shotgun, killing three people and injuring a fourth.
Briscoe and Logan track him down from his subscription to a racist magazine, and find that he fits a profile developed by Elizabeth Olivet of a loner who lives in the neighborhood, blames African-Americans for his problems, and owns a shotgun. They bring Tunney in for questioning, and arrest him when the surviving victim identifies his voice from a voice lineup. While in jail, he is stabbed by an African-American inmate, further fueling his racism.
Tunney goes to trial, represented by African-American lawyer Horace McCoy. When someone commits a copycat murder, DA Jack McCoy drafts a motion to have Tunney released on bail due to reasonable doubt about his guilt, which is granted. Once Tunney is out on the street, he tries to shoot an African-American woman, who shoots and kills him in self-defense. (L&O: "Profile")