DALLAS He was unarmed, and he committed no crime.
But a Dallas police officer shot and killed Tobias Mackey in October 2010.
This case is complicated, so we want to walk you through the timeline:
After the shooting, the Dallas County district attorney's office, the Dallas Police Department, and local FBI officials cleared Officer Matthew Tate, who shot Mackey.
No charges were filed, and no one was disciplined.
But Mackey's mother sued the city, which took another look at the facts of the case and offered her hundreds of thousands of dollars.
She turned down the cash and instead went to the U.S. Justice Department, which opened a civil rights case that went to trial on Tuesday.
There was drama in the courtroom -- along with critical testimony. Mackey's mother, Sheila Lewis, became emotional when crime scene photographs of her son were shown to the jury.
'My baby!' she cried out, angering Judge Reed O'Connor, who ordered that Lewis be removed from the courtroom. The judge threatened to declare a mistrial if there were any further outbursts.
Lewis is suing the City of Dallas and Officer Matthew Tate for shooting Mackey seven times, resulting in his death in October 2010.
In opening arguments, Lewis' attorney told the jury they will see that there was 'no evidence Mackey committed a crime, no observation of criminal activity, and no weapon in his hand when he was shot.'
The defense contends this was an unnecessary shooting because officers had no reasonable argument to fear for their lives.
One of the witnesses for the plaintiffs was Officer Tate's own supervisor, Sgt. Kenneth Chapin. Chapin testified that on the night of the shooting, he was only five feet from Mackey and Tate.
Chapin said he never saw Mackey as a threat, and that deadly force was not justified.
Mackey was walking through an apartment complex when he was approached by officers who were there to do a criminal trespass sweep looking for possible troublemakers.
Also shot that same night was 12-year-old Xavier Collins, who was wounded in the arm.
Defense attorneys said Tate feared for his life because Mackey ignored commands. Tate thought Mackey he was reaching in his pants for a weapon.
'Hindsight is 20/20,' a defense lawyer told the jury. 'Your job is to see if Officer Tate was reasonable in what he did. The death was tragic. Tobias Mackey did not show his hands; had he done that, Tobias Mackey would be alive today.'
Chapin also testified that Dallas police officers need to be told during training that just because they can shoot somebody, doesn't mean that they can. He said police department applicants need to be vetted better when it comes to this issue.
The City of Dallas stands to lose millions of dollars if they lose this case.