When police react to an imminent threat of what they believe is a drawn and pointed weapon, they are trained to respond with lethal force.
In almost all cases, officers' response ends the threat. In many cases, the suspect with the weapon is killed or injured. In a few tragic cases, a subsequent investigation shows the suspect did not have a weapon but some other object that looked like one in the heat of the moment.
Members of the Chattanooga police have killed two people in the last month who had drawn weapons or were thought to have drawn weapons.
In both cases, the families of the dead men say police reacted with too much force.
Investigations are continuing in the deaths of convicted felon Roger Heard Jr. and Howard School student David Lopez, and until they are finished no one will be able to say conclusively whether all proper procedures were followed in the incidents.
Families of the deceased are free to seek legal representation, to make whatever claims they like, to allege false things against law enforcement. Police, on the other hand, are urged to keep quiet, to not defend themselves against accusations, to let the investigation take its course.
It's not a pleasant time for either side. Families grieve their loved ones, no matter their loved ones' role in the actions that led to their deaths. Members of law enforcement do not glory in having killed someone. Officers are placed on leave, surely deeply ponder their own actions and must await the conclusion of investigations before being told whether their actions — taken in an instant — are deemed proper.
On Thursday, members of Lopez's family — through activist organization Concerned Citizens for Justice and Semillas TN — released a statement saying their son was holding a phone, not a gun, when police shot him on Sept. 3. They say the hail of gunfire that brought him down left 25 bullet holes in the walls and belongings in their home.
Police had been called to the house the night before by Lopez's father, who said he thought his son was having a mental health crisis after a fight with his girlfriend. Law enforcement officials said the teenager twice pointed a gun at them and would not respond to commands.
(READ MORE: 4 Chattanooga officers on leave after fatal police shooting that killed teen)
At some point they removed his family from the house for their safety, called a SWAT team to negotiate with the boy and apparently used a bullhorn and a robot to get him to leave the house. When he eventually began to emerge from a back door, showing what was believed to be a gun, he was shot.
Lopez's family doesn't believe police gave him the space to properly exit the house and are seeking unedited bodycam and dashboard video, 911 audio, the autopsy report and other relevant materials in the incident to back up their claims. None of that has been released to the public.
They also maintain a mental health counselor or behavior specialist should have been called.
Earlier this week, attorneys along with Heard's family alleged Chattanooga police used excessive force when they shot him Aug. 11 after he pulled a gun on them during an attempt to serve warrants on him at an East Third Street gas station.
Attorneys said police violated the man's constitutional rights by continuing to shoot him when he was on the ground and acted recklessly and irresponsibly when serving the warrants.
"Everything they said about my son, the way they put him down, they did not know him as he was, not now," Heard's mother, Gloria Lewis, said during a news conference at the foot of City Hall steps. "My son was a changed man, trying to provide for his kids and family. They took the joy out of my life."
However, video released to the public shows Heard — for whom it was illegal to have a gun because of his felony convictions — pulling a gun to shoot the approaching plainclothes officers who had emerged from an unmarked car.
Family members say the warrants should have been served elsewhere in a quieter, less populated place by officers wearing uniforms. Like the Lopez family, they're also seeking the release of more video and other relevant information.
The Heard case, at the direction of District Attorney Coty Wamp, is being evaluated by the Tennessee Bureau of Investigation, though she has said she thought the shooting was justified.
In both cases and as is routine, the officers who fired the shots were placed on leave.
Time will tell what the investigations will reveal, but if the public wants to feel safe in their cities — and polls show all demographics of people say they do — law enforcement must be properly trained but also given the leeway to make the very best decisions they can in situations where their lives and those of others are thought to be an imminent danger.