WASHINGTON - The conviction of a Dallas police officer this week on charges of killing an unarmed teenager has stood out for its rarity.
Roy Oliver, who was sentenced to 15 years in prison on Wednesday for the killing of 15-year-old high school freshman Jordan Edwards in 2017, became only the sixth police officer convicted in an on-duty fatal shooting incident since 2005, a period that has seen thousands of fatal police shootings.
While most of those shootings were found to be justified, civil rights advocates say they hope this week's conviction will lead to policies that put an end to a wave of questionable police shootings that have exacerbated tensions in some American communities in recent years.
"It can serve as an example of what can and should be done," said Hillary Shelton, senior vice president for advocacy and policy at the National Association for the Advancement of Colored People, the nation's oldest civil rights organization. "Hopefully, we'll be able to utilize it as something to get more local police departments, state police organizations, and even those at the federal level to change how they do business."
Randy Sutton, a retired Las Vegas Police Department officer and author of A Cop's Life, praised Oliver's conviction but said the Dallas incident was an aberration in police shootings.
"This was not a justified shooting by the police," Sutton said. "To try and lump this shooting [with other high profile shootings of blacks by white police officers] and then characterize these shootings as excessive and using it in anti-police rhetoric, I find it offensive."
On-duty police officers kill between 900 and 1,000 suspects each year, a figure that has remained consistent in recent years, according to data tracked by criminologist Phil Stinson at Bowling Green State University.
Yet only 93 police officers have been charged with murder or manslaughter resulting from an on-duty fatal shooting since 2005, and only 33 have been convicted of a crime related to the shootings, according to Stinson.
Of those, only six were convicted of murder or manslaughter, and four of those convictions were overturned on appeal. In all four cases, the officers were later tried and convicted on separate federal charges related to the incidents and received lengthy prison sentences.
"In most of these cases the officers were found to have been justified," Stinson said.
The legal standard determining when an officer can use deadly force was established in two Supreme Court cases from the 1980s, and most police department guidelines on the use of firearms against suspects are based on these rulings.
In Tennessee v. Garner, the court ruled in 1985 that a police officer may use deadly force against a fleeing suspect only when he has a reasonable belief that the suspect poses a significant threat of death or bodily injury to the officer or to others.
In Graham v. Connor, the court established in 1989 an "objective reasonable standard" for determining whether an officer had used excessive force.
According to these rulings, "a police officer is justified in using deadly force if the officer has a reasonable apprehension of an imminent threat of serious bodily injury or deadly force being used against the officer or somebody else," Stinson said.
On the other hand, "if an officer subjectively believes that there was an imminent threat but their belief was not objectively reasonable, then the officer is not legally justified and cannot assert that as an affirmative defense to defeat a conviction," Stinson said.
That is how Oliver ended up getting convicted. On the stand, Oliver asserted that he fired on a car in which Edwards and his friends were riding because he wanted to protect his partner who, Oliver believed, would be run over by the vehicle. But the partner, Tyler Gross, had already testified that he did not fear for his life and saw no need to shoot at the car.
Yet critics say police department policies on the use of deadly force are unclear and inconsistent, sometimes leading to excessive use of force.
"We're looking at these problems and we want them fixed," Shelton of the NAACP said. "And we want to make sure those policies are put in place so we understand when you can and when you cannot use deadly force."
Sutton said police department procedures vary from agency to agency, but when it comes to the use of deadly force all agencies abide by the Graham v. Connor ruling.
In police misconduct cases, officers are almost always charged with state crimes and tried in state courts. The Justice Department rarely prosecutes police officers and does so only when local prosecutors fail to obtain a conviction in a clearly egregious case or the defendant receives a light prison sentence.
Often, the officers are charged under a statute making it a crime to deprive an individual of his civil rights.
Amid a spate of high-profile shootings of unarmed black people by white police officers in recent years, the Justice Department under the Obama administration prioritized cracking down on police abuse.
Police departments involved in racially charged shootings were investigated, a handful of officers were charged with civil rights violations, and court-supervised consent decrees to reform the departments were entered into.
The Justice Department under the Trump administration continues to investigate police misconduct. According to press announcements by the department, the department has brought 11 indictments and received four convictions and nine guilty pleas in police misconduct cases since January 2017. Nearly all the cases involved assault or use of excessive force. None involved a fatal shooting.
Attorney General Jeff Sessions has said that while the Justice Department is committed to addressing police misconduct, "the vast majority of men and women in law enforcement are good people, who have chosen to do tremendously hard and dangerous jobs because they want to protect us all."
One of his first acts in office was to order the Justice Department to review all existing consent decrees with police departments, saying they "can reduce the morale of police officers."
Stinson said that while the number of police misconduct cases prosecuted by the current Justice Department is "surprisingly low" compared to historical norms, the figures do not necessarily suggest the "feds aren't doing their jobs."
"If local prosecutors are prosecuting these cases when they believe that an officer has committed a crime, there is no need for the Justice Department to invoke the federal criminal deprivation of civil rights statute. It's just unnecessary," Stinson said.