Police in the US...

The US police force has faced a great deal of criticism, first the three incidences with the video-cellphones where police officers, in one they beat a suspect which was already on the ground and defenseless, in another a student at UCLA was tasered repeatedly and finally the supposedly unprovoked attack of police officers against a group of pedestrians.

YouTube videos...
Police Brutality video
The UCLA student
The 'unprovoked' attack

These incidences and the more recent incidence where police officers shot around 50 bullets into a car in which a groom and his too friends where just leaving a strip club after a bachelor-party. The groom was killed, one of his friends had to brought onto Intensive-care station while the other friend was injured but remained in a stable condition. The police supposedly acted out of fear of an armed "altercation", this incident.
This leads to question the methods employed by the US-police. These incidences are not concentrated in one area but have taken place in different places which is why it seems to be national and not regional problem.

Article links...
NY rally deplores police shooting (BBC)
Cops Taser UCLA Student (ABC)