I'm a band parent. These routines are complex and elaborately choreographed. It takes the kids hours and hours of practice over several weeks to learn them. This was likely the routine chosen for the entire marching band season. They can't just come up with some spur of the moment routine and expect it to work. It is unfortunate that this routine was chosen. The band director, choreographers, and coaches should have known better.Onto the specific content here, the information provided does not support the claims of the thread title, and the OP conveniently omitted the fact that the halftime show as based on a movie. It seems like the performance was depicting a hostage situation breaking out in a hospital, not the killing of police.
Another piece of information that does not seem to be available at the moment, is whether this performance was recently implemented, or whether this was the band's ongoing halftime show for the season. School band halftime shows aren't slapped together overnight, and usually involve months of planning and preparation. I would be amazed if a high school marching band had the proficiency to first plan a complete choreography program, learn the choreography, then learn all the music, all in a matter of one week.
There seems to be more to this story that has the potential to impart significant nuance. Was this all part of the plan since the beginning of the season and they only now have completed preparations for this portion of the program? Was this a last minute alteration to the band's existing program? Was this meant to be part of a misguided attempt to reflect the community's recent pain?