"Just because we may not like the way things happened in the case today doesn't mean that Cincinnati is not going to move forward", the mayor said.
She called on the Cincinnati community to join them in "peaceful protest" of what she called an "unjust result".
DuBose's shooting made national headlines in 2015 after video of the incident recorded by Tensing's body camera showed the officer shooting DuBose point-blank in the head.
Mr Tensing later said that he had shot because he feared that he could be run over by the auto as Mr DuBose tried to get away. But DuBose, with the window down, puts his hand on the door to keep it closed. The then 25-year-old officer said he feared for his life after his arm became trapped inside DuBose's vehicle. Prosecutors contended that he was not actually in danger and had exaggerated his account.
Ray Tensing, the former University of Cincinnati police officer, testifying on the seventh day of his retrial in Hamilton County Common Pleas earlier this month at the Hamilton County Courthouse in Cincinnati. That process won't proceed until after the criminal case against him has concluded.
On Friday, a grand jury in OR declined to indict a police officer who killed a 24-year-old man, who was allegedly armed with a knife. The defense says Tensing, who pleaded not guilty, was scared DuBose would use his auto to kill him, so Tensing acted reasonably to try to stop the threat, The AP said.
But an expert said his frame-by-frame analysis of Mr Tensing's body camera video showed he was not being dragged by the auto. In recent years, the number of officers prosecuted in fatal shootings has increased, which experts attribute to a combination of more video evidence as well as political pressure.
The ruling on Friday was the latest in a series of high-profile trials of police officers who have gunned down black men. On Wednesday, a white officer shot an off-duty black colleague in the city of St. Louis - known for its proximity to Ferguson, where white officer Darren Wilson killed unarmed black teen Michael Brown - when he attempted to assist with an arrest. DuBose's family has called for another retrial.
Tensing's trial was the third to reach a conclusion over the past week.
If convicted, Tensing could face 15 years to life in prison. All three victims were black.
After 30 hours of deliberations, jurors said they couldn't reach a unanimous decision on either of the two charges Tensing faced - murder and voluntary manslaughter. Thirty-four of those cases have ended in non-convictions.