Frank Joseph Mazzacco Jr. was a 65-year-old longtime Trenton public-school teacher and one-time local union president who died at Hunterdon Medical Center in Flemington on June 24, 1996. At the time his death was recorded as a hospital passing and he was later buried at Greenwood Cemetery in Hamilton, Mercer County.

Years later investigators linked a cluster of sudden patient fatalities at Hunterdon in 1996 to critical-care nurse Charles Cullen, who confessed to administering lethal doses of medications, especially digoxin, to patients at multiple hospitals. Public victim lists compiled during prosecutions include Mazzacco among the New Jersey patients Cullen acknowledged killing; Cullen later pleaded guilty and received multiple life sentences.