Customers found 16-year-old Aref Mohamed shot to death at the back of the Stratford store back in 1996.
The governor is also offering a reward for information leading to the death of Saul Herrera.
The 24-year-old was shot and killed in July 2007 at his home after he and his friends got into an argument with another group.
More than 200 rewards have been offered under the governor's reward program which began in 1967. 19 have been paid.