Sterling's family and demonstrators quickly questioned whether Sterling, who carried no weapon, posed a danger to the officers. Over the past several months, the case has been presented to a grand jury, according to a witness who testified and an official with knowledge of the investigation, but no conclusions have been announced.
"We miss him dearly every single day. Mother's Day and Father's Day have come and gone, and were particularly difficult without Terrence this year. It is disheartening that the criminal investigation continues without anyone being charged or held accountable for Terrence's death and this delay has taken a real toll on our family," Sterling's parents, Isaac and Florence, and sister Chrystal said in a statement to The Washington Post.
The statement, released by the family's attorneys, is the first public comment from the family since Sterling's death.
"Terrence deserves justice. Justice for Terrence, and really all of us, requires an expeditious and transparent criminal investigation," the family said.
The U.S. attorney's office for the District declined to comment on the status of the investigation.
The Sterling shooting occurred after a city-sponsored report in 2016 criticized police and prosecutors for what it called "excessive delays" in the investigation of fatal shootings by police officers.
Michael Bromwich, a former inspector general for the Justice Department and a former independent monitor for the D.C. police, met with prosecutors and D.C. police officers in 2015 to investigate use-of-force cases. He prepared a 123-page report titled The Durability of Police Reform: The Metropolitan Police Department and Use of Force. The report was commissioned by D.C. Auditor Kathleen Patterson.
During his investigation, Bromwich said, prosecutors told him that their office has never filed criminal charges against an officer for a fatal on-duty shooting.
"I was surprised that there had never been one. I thought zero was a low number. If I had heard there was one or two, I would have expected that," Bromwich said in an interview. "But we're talking none."
Bromwich's team reviewed 21 officer-involved fatal shootings by police that occurred between Jan. 26, 2009, and Dec. 22, 2014. The average time a case was pending before prosecutors, he found, was more than 19 months.
The report said prosecutors explained that the delays were largely because of internal checks and balances within the U.S. attorney's office that often involved several layers of reviews of evidence and information by senior officials within the office.
Bromwich's team recommended that criminal investigations for fatal police shootings should be completed within six months. He noted that internal police department investigations, which are used to decide whether an officer who has been on leave after a shooting can return to active duty, are often delayed until prosecutors complete their review.
The U.S. attorney filed a response to Bromwich's report, noting that the office relies on evidence gathered by multiple agencies and saying that six months was not realistic to complete an investigation. Instead, the office suggested about nine months, which is the amount of time under D.C. law that prosecutors have to pursue a grand jury indictment against a murder suspect who is jailed and awaiting trial.
Jonathan M. Malis, chief of the criminal division for the U.S. attorney's office, wrote in the response to the report that "nine months provides a reasonable amount of time to investigate and review those types of alleged criminal violations, which includes the time required to obtain, analyze and review the types of external, third-party reports inherent in such complex criminal investigations."
D.C. Deputy Mayor Kevin Donahue said the mayor's office has not been briefed on the status of the Sterling investigation, which is in the hands of prosecutors.
"We want an investigation to be thorough, and we want a decision to come out as quickly as possible but without sacrificing the thoroughness of the investigation," Donahue said.
The Sterling altercation began about 4:20 a.m., when officers got a call about a motorcycle driving erratically in the Adams Morgan area. Later, police saw the motorcycle near Third and M streets in Northwest Washington near the Third Street tunnel.
Two witnesses have told The Post that the marked police cruiser pulled into the roadway ahead of the motorcycle.
Police said as the officer in the passenger seat, Brian Trainer, began to exit, his door was struck by the motorcycle. Trainer fired his weapon.
The witness said in interviews that the crash did not appear deliberate and they thought that Sterling was trying to move around the police car.
Trainer, who has been with the police department for more than four years, was wearing a body camera but did not turn it on until minutes after the shooting. Afterward, the police department changed its policy requiring officers to turn on their cameras immediately when they respond to a police call.
Trainer and the second officer, who has not been identified, have been placed on leave pending the outcome of the investigation.
Sterling's family, meanwhile, continues to wait. They think that Sterling was headed that night to the Fort Washington home he shared with his parents.
The family, through their attorney Jason Downs, has filed a $50 million civil lawsuit against the District and the police.
Downs is a lawyer at the same firm of Baltimore attorney William "Billy" Murphy, who represented the family of Freddie Gray, 25, who died in 2015 after being injured in police custody. The city of Baltimore later settled with the Gray family for $6.4 million.
Sterling's family said they think prosecutors move faster in cases in which a shooter is not a police officer.
"It is hard to reconcile how quickly the police will charge our citizens yet, when it's one of their own, it seems as if they are looking for any way to avoid it," the family said in their statement.