I don't know details of this case, but in general the police don't have a duty to act in specific circumstances. They're more for our overall well being:

http://www.nytimes.com/2005/06/28/politics/justices-rule-pol...

At the risk of being "someone is wrong on the Internet"[1], I'd venture that the police did not face disciplinary action.

[1] https://xkcd.com/386/