The unidentified Stamford juvenile was charged with felony murder, murder, conspiracy to commit robbery, larceny and carrying a pistol without a permit, Harris said.
He is being held on $1 million bond.
“An additional arrest is expected shortly,” Harris added.
Slinsky was shot twice in the head on Aug. 27, 2016, on Wood Terrace in Bridgeport, during a drug deal gone bad, police said.
The juvenile is the second person to be arrested in connection with the murder.
Last March, 19-year-old Stamford resident Jeremy Middleton was charged with murder, conspiracy to commit murder and robbery in connection with his death.
At the time of his death, police said Slinsky had struggled with marijuana use and was part of a teacher sex case in Stamford.
As a student at Stamford High School in 2014, Slinsky and an unidentified friend regularly smoked pot supplied by former English teacher Danielle Watkins, who is now in prison for having a sexual relationship with the friend.
In the months before he was shot to death, Slinsky received a $100,000 settlement from the city for the school administration’s failure to contact police immediately about the teacher's activities.
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