Joseph Soriano is a detective assigned to the Internal Affairs Division, investigating Lionel Fusco about the disappearance of Detective Stills.
After Louis Azarello informed the police of Fusco's involvement with Stills and HR, Soriano started investigating him.
He cornered Fusco at the station and took his badge and gun. He told Fusco that Azarello had flipped on him and informed IAB of the murders he had committed for Stills. He also told Fusco that they have information on where Fusco buried Stills body. However, Carter - with help of Bear - removed the body and when Soriano got to the site he found the ground dug up with no body. Enraged, Soriano accused Fusco of killing Stills and promised to hang it on him. Fusco told him that he's wrong and walked away. His investigation ended fully when Finch got Elias to "convince" Azarello to recant his confession. (“In Extremis”)
Three years after, he is tasked along with S. A. Martin LeRoux to question Fusco about the deaths of Dominic and Elias. When LeRoux clears Fusco of any wrongdoings Soriano remains skeptical and questions LeRoux regarding the ballistic report.
Samaritan then marks him as an obstructionist and arranges for him to have a heart attack using his pacemaker, killing Soriano. Fusco is informed of his death by IAB Agent Glenda Sumner. (“B.S.O.D.”)
