Creator Backlash: Brian Garfield, the author of the original novel, sued the filmmakers for twisting the source material (ironically, the point of Garfield's novel was that vigilante tactics weren't the solution). You can probably guess from the four subsequent sequels that he lost.
The first movie has Jeff Goldblum in his screen debut playing one of the criminals who attack Kersey's wife and daughter. Denzel Washington and Sonia Manzano (Sesame Street's Maria) also have tiny bit parts; as a mugger and a grocery clerk respectively. Christopher Guest also appears as a patrolman.