Kenneth Chamberlain did not have to die. He did nothing wrong. He had not committed any crime, was not a terrorist, a fugitive, or holding any hostages. He was an emotionally disturbed 68-year-old African-American man who lived alone in his ground-floor apartment in White Plains when his heart monitor accidentally went off at 5 a.m. last Nov. 19, triggering a medical alert and the dispatch of White Plains police to his residence. What followed from this seemingly inconsequential event was an ugly, violent and rapidly escalating confrontation between Chamberlain and the White Plains police that ended with Chamberlain shot to death. Why did this happen, and what can we learn from it?