coroner

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A public officer whose primary function is to investigate any death thought to be of other than natural causes.

from The Century Dictionary.

• noun A county or municipal officer formerly charged with the interests of the private property of the crown, but whose main function in modern times is to hold inquest on the bodies of those who may be supposed to have died violent deaths.

from the GNU version of the Collaborative International Dictionary of English.

• noun An officer of the peace whose principal duty is to inquire, with the help of a jury, into the cause of any violent, sudden or mysterious death, or death in prison, usually on sight of the body and at the place where the death occurred.
• noun See under Inquest.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A public official who presides over an inquest into unnatural deaths.
• noun Canada A medical doctor who performs autopsies and determines time and cause of death from a scientific standpoint.
• noun The administrative head of a sheading.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a public official who investigates by inquest any death not due to natural causes