CSI Cold Case File" Gang Hit Overkill"

The execution-style killings inside a North York fish warehouse made no sense.

Two part-time workers with no criminal ties were gunned down in what looked like a mob hit.

After an investigation that went nowhere, the homicide squad's notes were put in four banker's boxes where they sat for a decade -- another cold case file.

The first break in the case came 800 km away after a New York City heroin ring was busted in 2004. In exchange for leniency, one of the arrested offered information about two men who were mistakenly killed in Toronto and who killed them.

An American gang leader and his lieutenant now face at least 20 years in jail for planning and botching a hit in Toronto 14 years ago that left two innocent men dead.