After four years abroad, Detective Lupo returns to the United States to find his brother committed suicide by lethal injection because of his incurable illness. Before the case is closed, another man is found dead, having killed himself in an identical fashion. Lieutenant Van Buren permits Lupo to work the case alongside fellow Detective Ed Green.
Lupo and Green are suspicious of a recent parolee formerly known as "Dr. Death," and through further investigation they are inclined to believe "Dr. Death's" daughter could be a follower of her father's work.
An explosion hospitalizes a pregnant guard, leading Detectives Ed Green and Cyrus Lupo to a Gen-Tech scientist whose lab is housed in the same building where the bomb is delivered. When the detectives discover the injured security guard had been one of the doctor's research subjects, ADAs Michael Cutter and Connie Rubirosa suspect the security guard's brother-in-law.
When a pair of men's pants goes missing from a drycleaner, Detectives Ed Green and Cyrus Lupo suspect the lost pants may be linked to the gruesome murder of a young lawyer. The evidence trail soon leads the detectives to a suspicious businessman who may be covering up a forbidden affair with a co-worker, and perhaps, far more.
When a Caucasian teenage boy and young African American girl are found dead near a neighborhood playground, Detectives Cyrus Lupo and Ed Green have trouble getting witnesses to talk after realizing the boy was targeted and the girl was killed accidentally.
When three roommates are found dead in their apartment Detectives Ed Green and Cyrus Lupo's initial examination of the crime scene suggests a murder-suicide amongst jealous lovers.
After a mother and daughter are killed in a hit and run accident, Detectives Green and Lupo track down the vehicle and find only a stack of $100 bills left inside.
A murdered woman is found in an alleyway dumpster after a riot at an immigration rally. Detectives Cyrus Lupo and Ed Green's investigation leads to an auxiliary cop's over zealous attempt to stop the riot. The political nature of the case elevates tension in the DA's office as DA Jack McCoy assigns ADA Josh Lethem to prosecute the case. But Lethem has his own biased agenda, bringing McCoy's liberal background into question.
Dr. Mark Burns is found murdered in his hotel room while attending an out-of-town convention. Detectives Lupo and Green learn that Dr. Burns' made a large withdrawal from his bank account moments before he was murdered.
Two inebriated high-school girls, Kelly Daugherty and Anne-Marie Liscomb, are agitated after their car is towed at a party. Liscomb walks off to make a phone call for a ride, and is found dead in a dumpster days later.
A psychiatrist is found shot to death in his office, and Detectives Ed Green and Cyrus Lupo initially suspect one of his young patients. Clues lead the detectives to the doctor's jealous and much younger wife, Catherine.
The police break up a dog-fighting ring, and discover a woman's finger inside one of the dead animals. The finger is identified as belonging to Lauren Vance, soon-to-be ex-wife of Marty Vance, after her body turns up near a dog breeder.
Art dealer Audrey Lortell is found stoned to death. Detectives Cyrus Lupo and Ed Green suspect the dealer's killing may have been linked to some of the cultural and religious artwork showcased in her gallery.
A part-time referee is found murdered, and Detectives Ed Green and Cyrus Lupo investigate the victim's gambling habits. The detectives are led to notorious hustler, Bunny, a familiar face from Detective Green's past.
A novelist is found dead in her car, which appears to be a suicide at first inspection, but Detectives Cyrus Lupo and Kevin Bernard have reason to believe a cult known as "Systemotics" is involved.
When legal aid striker Frank Dresner is killed outside the courthouse, the sand in Dresner's wounds lead Detectives Lupo and Bernard to investigate a greensmen at a local golf course.
Automobile mechanic Eric Greenwood is found murdered outside of a bar leading Detectives Cyrus Lupo and Kevin Bernard to question the victim's boss, Bob Munsen.
Jeweler Victor Madison is found murdered, and Detectives Cyrus Lupo and Kevin Bernard investigate a peculiar deposit in Madison's bank account. The deposit leads the detectives to investigate Madison's brother-in-law, Frank Beezley, who was running an illegal prostitution ring, The Excalibur Club. Closing the case proves to be a challenge, when Jack McCoy's job is threatened.