John Giuca was a Brooklyn native born around 1983. He lived with his mother, Doreen Giuliano, and had a reputation as a neighborhood guy who liked to hang out with friends. He didn’t attend college at the time of the crime, and instead, was reportedly running in a crowd known for partying and minor criminal activities. Giuca had previously been arrested in July 2004 in Florida, where he was accused of assault for allegedly firing a gun at a group of men, though the charges were later dropped. In September of the same year, he was arrested in Brooklyn for selling drugs while wearing a bulletproof vest.

Despite this turbulent lifestyle, Giuca had no prior convictions when he was arrested in connection with the 2003 murder of Fairfield University student Mark Fisher. At the time, he was known to associate with a loose-knit group of young men referred to in court as the "Ghetto Mafia," a group portrayed by prosecutors as driven by machismo and a hunger for street cred.

His mother would later become a notable figure in the fight for his release, gaining attention for going undercover to investigate one of his jurors — an effort that earned her the nickname “Mother Justice.”

On the night of October 11, 2003, 19-year-old college sophomore Mark Fisher went out drinking with friends in Manhattan. During the night, he ran into fellow Fairfield student Angel DiPietro. Eventually, they met up with John Giuca, who invited everyone back to his home in Brooklyn after being denied entry to a bar. Fisher, DiPietro, and others agreed to go.

In the early morning hours of October 12, 2003, Fisher was found shot dead—five bullets in the chest, side, and back—on Argyle Road in Prospect Park South, Brooklyn. His body was wrapped in a yellow blanket from Giuca’s house. Police discovered shell casings from a .22-caliber gun at the scene. Though Fisher had some cash on him, his wallet was found discarded in a nearby sewer.

Giuca and Antonio Russo, a 17-year-old from the same neighborhood, were the last known people to see Fisher alive. After the murder, phone records showed a spike in calls between Russo and Giuca—26 calls within 24 hours. Russo also cut off his dreadlocks and fled to California days later.

Giuca was arrested on December 21, 2004, and charged with second-degree murder, first-degree manslaughter, robbery, and weapons possession. Prosecutors claimed Giuca gave Russo the murder weapon and orchestrated the killing as a gang initiation, citing testimonies from multiple witnesses, including Giuca’s girlfriend and his best friend, Albert Cleary.

Cleary testified that Giuca led Fisher outside where Russo was waiting with the gun. After Russo allegedly shot Fisher, he handed the gun back to Giuca, who then asked Cleary to dispose of it. Giuca’s former cellmate, John Avitto, also testified that Giuca confessed while speaking with his (mute) father on Rikers Island—a statement that drew major criticism and raised doubts.

In October 2005, both Giuca and Russo were convicted of second-degree murder and sentenced to 25 years to life.

2008–2015: Giuca filed several appeals, citing juror misconduct and prosecutorial failure to disclose key information. Despite multiple filings, state and federal courts upheld his conviction.
2018: The New York State Appeals Court overturned his conviction due to the prosecution’s failure to share evidence related to a key witness and ordered a new trial.
2018: In March, Russo submitted a written confession claiming sole responsibility for Fisher’s murder and that the gun used was his.
2019: The New York Court of Appeals reversed the 2018 decision and reinstated Giuca’s conviction, ruling that the withheld evidence would not have affected the trial’s outcome.
2021–present: Giuca’s legal team filed another motion to vacate his conviction. He remains in prison as the legal battle continues.

His mother, Doreen Giuliano, remains a vocal advocate for his innocence. She famously went undercover as “Dee Quinn” to befriend a juror she believed was biased against her son. While criticized for her methods, she brought renewed media attention to Giuca’s case.