Grant, the 34-year-old father of twin boys, was behind the wheel of the luxury sedan, parked with its hazard lights on, when a grey Honda Accord with the robbers inside stopped across the street about 4:45 a.m.
The three robbers jumped out of their car, leaving its driver behind the wheel as they charged toward the BMW.
Grant, whose sons are age 3, was driving away from the mayhem when he was shot in the head by by one of the crooks with an apparent silencer on his gun.
Chacon, a Brooklyn resident and father of an 11-year-old daughter, was recovering in the intensive care unit Tuesday at Harlem Hospital.
“He asked me for his friend and I said ‘I don’t know,’ because I didn’t want to say to him.
According to Grant Sr., his slain son — who like his dad worked construction — owned a pricey watch along with a gold and diamond chain, worth about $2,500, purchased while living at the dad’s home in Rosedale, Queens.