When the S.W.A.T. team enters the room to rescue the hostages, they are supposed to throw in stun/concussion grenades to blind the hostage-takers. The props used in the movie were explosive grenades, which would have killed the hostages, the perpetrators, and possibly even the rescuers themselves.
The helicopter used in the official cover art is a Soviet/Russian Mi-8/17 - which definitely is one of the last helicopters you would ever have seen used by U.S. Law Enforcement in the 1990's (and to this day).