A candy bar, a wallet, even a pair of baggy pants can draw deadly police gunfire.
The killing of a hairbrush-brandishing teenager last week was the latest instance of police shootings in which officers reacted to what they erroneously feared was a weapon. It has revived debate over the use of force, perceptions of threats and police training.
"We have cases like that all over the country where it can be a wallet, a cellphone, a can of Coca-Cola and officers have fired the weapon," said Scott Greenwood, a Cincinnati attorney who has worked on police use-of-force cases across the country and who is a general counsel for the American Civil Liberties Union.
"It does not necessarily mean it was excessive use of force," he said. "However, those types of incidents do give rise to greater suspicion on the part of the public about how police use force and they call into question the training departments are using to train officers to perceive and respond to threats."
The New York Police Department (NYPD) says the officers who fired 20 shots at 18-year-old Khiel Coppin on Nov. 12 were justified in their use of force. The mentally ill teenager approached officers outside his mother's home with a black object in his hand -- the hairbrush -- and ignored orders to stop.
The officers were responding to an emergency call in which Coppin could be heard in the background saying he had a gun. But in a second emergency call Coppin's mother told the operator her son was not armed, and after officers arrived she repeated that to them.
"Why did the police not heed the warnings ... that her son was unarmed?" said Paul Wooten, the family's attorney. "Why was it necessary for the overwhelming use of deadly force? Five police officers, 20 shots, eight hits. Is there no proportionality?"
Last year, NYPD officers fired 50 bullets at three unarmed men in a car, killing Sean Bell on his wedding day and seriously wounding his two friends. Three officers are scheduled for trial in February.
In 1999, four New York City undercover officers fired 41 shots at West African immigrant Amadou Diallo, striking him 19 times, when the 22-year-old man reached for his wallet while standing in an apartment building vestibule. The officers said they thought Diallo was reaching for a gun.
The 2001 Cincinnati police killing of Timothy Thomas -- the 15th black resident to die at police hands since 1995 -- led to the city's worst civil unrest since the assassination of Martin Luther King. Thomas was unarmed, but was reaching to pull up his baggy pants while he was being chased.
In that case, as in other police shootings, the officer who fired said his actions were triggered by fear for his own safety.
At least 64 US law enforcement officers have been killed by gunshots this year, according to the National Law Enforcement Memorial Fund.
Andre Burgess was walking down a New York street in 1997 when an undercover federal agent shot him in the thigh, saying he thought the foil-wrapped Three Musketeers candy bar in his hand was a gun.
Violent confrontations between police and suspects occur daily in big cities, and officers must often make snap judgments on the use of force.
On Sunday, officers in the New York City borough of Brooklyn shot two people who they believed were dangerous; one was a suspect in a stabbing who police said advanced on officers with a broken bottle.