The Baltimore policeman facing the most serious charges in the death of Freddie Gray was acquitted on Thursday, in a case that sparked riots last year and fuelled a national debate over how US police treat young black men.
This time the trial was for the officer who drove the van in which Gray was being taken to a police station and suffered an ultimately fatal spine injury.
Caesar Goodson was acquitted on all charges including second degree murder and manslaughter.
Goodson was the third of six officers charged over the death of the 25-year-old, which triggered riots in Maryland's largest city last year. No guilty verdicts have been handed down in the three trials.
Because the state failed to meet its burden of proof in any of the seven charges against Goodson, "the verdict on all counts is not guilty," Judge Barry Williams, who presided over the case, told a packed court room.
Gray was arrested April 12, 2015 after fleeing at the sight of police, and suffered a broken spine while being transported in the back of a Baltimore police van, unsecured and with his hands and feet bound. He died a week later.
Williams had challenged state prosecutors' charge that Goodson had deliberately given Gray a "rough ride" in the back of the van, saying the state provided insufficient evidence of such "actions or intent" by Goodson.
Gray's relatives expressed disappointment with the verdict.
"This family is enormously frustrated, not just for themselves, but for this community," they said through family attorney William Murphy.
"We still have an unaddressed police brutality problem, not just in this city, where very little has changed, but in this nation."
Mayor Stephanie Rawlings-Blake said the officer would now face an administrative review and appealed for patience in allowing the process to run its course.
Baltimore officials this week called for calm in the city ahead of the verdict, stressing that authorities were prepared. The National Guard was on call as well.
Baltimore remained mainly tranquil in the aftermath.
There was, however, no shortage of public frustration, with protesters seething outside the courthouse, where several dozen people held up signs and demanded justice for Gray.
"There will be another rebellion because people are not going to stand by and stand for killer cops killing black people, brown people, poor people at will. They think that black lives don't mean a goddamn thing," said Baltimore resident Lee Patterson.
Murphy urged Baltimore residents, however disheartened, to remain peaceful.
"People should be calm. They should not react with unreasonable anger. There should be no disturbances in the wake of this trail," he said, even as he voiced the Gray family's deep disappointment.
"Can you imagine losing a son under circumstances shrouded basically in secrecy?" Murphy said.
"Can you imagine the frustration that nobody yet has been found culpable or liable for something that somebody did?" he said.
Meanwhile, Baltimore's police union said state attorney Marilyn Mosby's failure to convict anyone in the first three trials shows she over-reached with her "malicious prosecution" and urged her to drop all charges against the remaining officers.
'No credible evidence'
Judge Williams dwelled on the dispute between medical experts over exactly when Gray's critical injury occurred, saying his injuries were internal, thereby making it impossible to determine where and when they were sustained.
The judge also declined to convict Goodson for assault or reckless endangerment for failing to seatbelt Gray in the back of the van. He said Goodson assessed the danger level during the detention and determined there was an excessive security risk involved in entering the van and fastening Gray's seatbelt.
"Simple carelessness is insufficient to establish the defendant's guilt," Williams said.
"There has been no credible evidence presented at this trial that the defendant intended for any crime to happen."
Goodson's seven charges included second degree depraved-heart murder, manslaughter by vehicle, second degree assault and reckless endangerment.
Tony Brooks, who works at a city sports arena, said he was resigned to police abuse, but still shocked at how regular it has become.
"This ain't the first time it's happened in Baltimore. It ain't gonna never stop," he told AFP.
"They're supposed to uphold the law and protect us, but they're killing -- and they're getting off free with it. New York, Texas, Cleveland," he said, citing recent cases of police brutality.
The two other officers tried in Gray-related cases - William Porter, whose trial ended in a hung jury in December, and Edward Nero, who was acquitted of all charges in May - were reportedly in the court room and seen hugging and shaking hands after the verdict.
Two other officers face trial next month and the final officer in September.