Except for the most hardline Anarchists, few would dispute the need for some type of constabulary\police force to further the interests of justice, broadly defined.
The real question is what type of constabulary\police force we shall have and how it shall derive its legitimacy.
And when a police force loses its legitimacy, but retains its weaponry and logistics, what shall we then call it? Back in 1789 France, the gendarmerie serving the 2nd Estate had lost most of its legitimacy but retained its weaponry. So in 2013 Los Angeles, the LAPD has lost much of its legitimacy but retains its weaponry.
The LAPD resembles just another gang with guns, one that operates under color of authority but without an undergirding of popular legitimacy. It no longer commands respect and only compels sullen obedience to its dictates through fear of its weaponry. As enforcers and goon squad for the 1%, the LAPD and other SoCal law enforcement agencies have thus through L'Affaire Dorner revealed themselves as a latter-day Praetorian Guard, serving the needs of empire and emperors while the masses are made wholly expendable.
When the masses lose their fear of its weaponry, the LAPD, and the 1% elite whose interests it protects and serves, shall be swept into the dustbin of history. That cannot come a moment too soon.