CINCINNATI — An officer who shoots at someone typically will undergo interviews and psychological evaluations and be placed on paid leave.
Unlike other killings, however, what happens next is not tracked. No one regularly chronicles the use of police force, how many people are killed in confrontations with officers or how many officers are prosecuted or convicted.
Officers are well-trained for the instant decisions they must make in life-and-death situations, such as last weekend in a Cincinnati suburb, when a teen who was shot to death opened fire from a sidewalk.
But watchdogs fear a lack of overall accountability.
"As a society, we are very lenient toward use of force by police," said Brigitt Keller, executive director of the National Police Accountability Project in New York City.
Ohio, for example, does not require an investigation of police shootings by an agency other than the one for which the officer works.
With no national standard that defines force — let alone consistent requirements for reporting it – it can be difficult to find reliable data and valid reports about the number of confrontations with police that turn violent.
According to the last-known comprehensive national study, published by the International Association of Chiefs of Police in 2001, officers used force in 3.6 out of every 10,000 calls over a two-year period.
Thomas Aveni, executive director of the Police Studies Council and a police officer in New Hampshire, has testified for the prosecution and in defense of officers in deadly shootings, during both criminal and civil trials.
"The fact is that a lot of police shootings involve errors in judgment," Aveni said. "People seem to think police are sadistic and want to shoot people. It's almost as if they think we have trophies on our wall with people we shot. It's just the opposite."
Criminal charges rare against police officers
In the Cincinnati area since 2001, only one officer has been charged after killing someone while on duty.
In that case, a Hamilton County judge found then-Cincinnati Police Officer Stephen Roach not guilty of negligent homicide in the April 2001 shooting death of Timothy Thomas.
The acquittal triggered four days of protests and riots in the worst civil unrest Cincinnati had experienced since the 1960s.
An officer convicted of criminal wrongdoing could face federal prison for violation of civil rights.
Officers across the nation train often for dangerous and sometimes life-threatening confrontations.
Last year, 111 federal, state and other law officers were killed in the line of duty, according to the National Law Enforcement Officers Memorial Fund. Of those, 33 were shot to death during a confrontation.
A few officers are charged with criminal wrongdoing after shooting someone. Last month, a grand jury indicted Charlotte-Mecklenburg, N.C., police Officer Randall Kerrick in the shooting death of an unarmed 28-year-old man. Kerrick was charged with voluntary manslaughter for shooting Jonathan Ferrell 10 times after responding to reports of a man trying to break into a home. Ferrell had wrecked his car and had pounded on a nearby resident's door to get help, police said. The resident thought someone was trying to break in. It was the first time in 30 years that a Charlotte police officer had been charged in an on-duty shooting.
Did officer fear for life? Was someone else in peril?
Police department policies on using deadly force differ from agency to agency. But in the end, shootings are typically judged by how the officer perceived the threat. Did he fear for his life? Was he trying to protect someone else from being killed?
The U.S. Supreme Court has ruled that use of force must be judged "from the perspective of a reasonable officer on the scene, rather than with the 20/20 vision of hindsight."
In that 1989 case, Graham v. Connor, the court noted that officers "are often forced to make split-second judgments in circumstances that are often tense, uncertain and rapidly evolving."
Aveni, the New Hampshire expert, said his group's research has shown that one in four police shootings involve an unarmed civilian and two-thirds occur in low-light situations where police mistake something in a subject's hand for a gun.
"The reason why there is such a divide between the public's perception of events is people perceive the cops know everything they need to know when they pull the trigger. But (police) have to process things that are ordinarily very ambiguous," Aveni said.
Keller, with the National Police Accountability Project, said stricter, more consistent standards are needed for when police officers can use deadly force. Holding officers accountable through discipline or prosecution could reduce instances of unjustified use of deadly force, she said.
"There should be more guidance as to what exactly qualifies," she said. "It's one of the more dangerous jobs, but in my view it does not justify the use of deadly force in every case whatsoever."