John Rosario, a 37-year-old Hispanic/Latino man from Waterbury, Connecticut, was described by loved ones as a hardworking father and mechanic. He was known for his sarcastic sense of humor, his outgoing personality, and for always being willing to help someone.
On the evening of March 19, 2023, police were called to a multifamily apartment building at 300 Hill Street at approximately 8:45 p.m. for a report of a gunshot victim.
Inside a vacant apartment, officers discovered John Rosario suffering from multiple gunshot wounds to his neck, chest, and stomach. He was pronounced dead at the scene shortly after.
The investigation revealed that two men armed with assault-style rifles and wearing face coverings had approached the rear of the residence just before the shooting. In April 2023, Waterbury police arrested their first suspect, 38-year-old Jose Cintron, a local resident. He was charged with murder, conspiracy to commit murder, and numerous weapons offenses, and was held on a $2 million bond.
Three months later, in July 2023, authorities apprehended a second suspect, 37-year-old Juan Carlos Lopez-Fontanez. He was extradited from Puerto Rico to Connecticut to face charges including murder and conspiracy to commit murder, with his bond set at $3 million. A third man, Solomon Lopez-Mejia, was later charged as the alleged driver in the homicide. According to prosecutors, the motive for the killing was that Cintron was angry about a relationship Rosario was having with Cintron's sister.
In November 2025, Juan Carlos Lopez-Fontanez pleaded guilty to murder under the Alford doctrine, meaning he did not admit guilt but acknowledged that prosecutors had enough evidence to convict him. As part of a plea agreement, he accepted a 30-year prison sentence. As of that month, the criminal cases against his co-defendants, Jose Cintron and Solomon Lopez-Mejia, remained pending.
