On Thursday, Michael Slager, a former police officer with the North Charleston, S.C. Police Department, was sentenced to twenty years in federal prison—not life imprisonment. Slager had pleaded guilty in May to a violation of Walter Scott’s civil rights, by acting under the color of law, in a shocking, caught-on-video slaying of the fleeing victim in April of 2015. Slager’s depraved actions—shooting an unarmed subject, who was running away, in the back—appear to be a clear-cut case of second-degree murder. The sentence, in my view, did not meet the gravity of the crime. The judge’s decision, however, was restricted by the limiting brackets of federal sentencing guidelines. But the message it sent reverberated throughout the nation. The perceived leniency sets our country on a path backwards, not forwards, in the efforts of law enforcement to work with communities of color.

Slager’s case is yet another criminal justice system failure to mete out appropriate punishment to a rogue “instrument of the state.” By failing to prosecute the disgraced ex-cop to the fullest extent of the law, the system will again—and should again—be questioned and challenged. Slager’s unconscionable actions cast undeserved shade on law enforcement’s administration of the complexities inherent in the “use of force” continuum. Simply put, he has made law enforcement’s job of protecting communities of color exponentially more difficult. The manner in which the case was federally charged—predicated by the state’s previous failure to convict Slager on second-degree murder charges—aggravated the damage inflicted by the system.

As a retired FBI supervisory special agent, I toiled nearly a quarter-century investigating and supervising criminal cases in places like Brownsville, Brooklyn, the South Bronx, and in New York State’s most violent enclave, per capita, the City of Newburgh. I have arrested countless drug dealers and violent street gang members. I have removed multiple weapons from inside waistbands and coat pockets, and have participated in and overseen multitudes of young black and brown men taken into custody, accused of a myriad of federal crimes.

It is a necessary but often unpleasant undertaking to place people under arrest. And the vast majority of law enforcement professionals take the responsibility seriously. They employ the minimum appropriate amount of force to effect an arrest. They treat those in their custodial care with respect, even while often enduring dangerous physical resistance and non-compliance.

Nevertheless, having worked in neighborhoods and barrios comprised of people of color, many of whom view police as an “occupying army,” I can understand their distrust and disdain. It stems from decades of fractured relationships with the law enforcement personnel sworn to protect and serve them. Even anecdotal evidence of mistreatment by one rogue cop can damage numerous positive interactions.

Now retired from the FBI, I have debated questionable police shootings in academic settings and on television panels. Often I am able to provide some context or clarity to a shaky cellphone video or decipher, for a general audience, a particular justified police tactic employed during a violent confrontation. There’s usually an explanation. Or, absent that, there’s a plausible benefit of the doubt to be considered.

In Slager’s case, there was no good explanation or benefit of the doubt. And here’s why:

The law enforcement standard for consideration during a review of the use of deadly force is asking this question: “How would a reasonable cop have responded?” “Reasonableness” for a law enforcement officer does not equate to that of a civilian—an average person. It takes into account a number of specific job-related factors, including the inherent difficulties that cops deal with in real time in their daily encounters. Police do not have the benefit of 20/20 hindsight or slow-motion rewind technology that the “online jurist” enjoys.

To wit:

Action is always faster than reaction. Even seemingly benign encounters can suddenly and unexpectedly spin out of control in a fraction of second. I know – I’ve seen it. A cop stands with gun drawn and trained on a subject. A distraction. A heartbeat. And someone with bad intentions can draw a secreted weapon and use it before the cop’s brain can cognitively assess the situation fully. But to wait can be fatal: If the suspect is armed, a bullet can instantaneously injure or kill an innocent person or the cop himself. A law enforcement officer must therefore interpret and anticipate a suspect’s movements and words, winnow out what might be a duplicitous ruse, and make a split second decision to shoot before all of the information can be completely processed.

Managing fear. Contrary to popular belief, cops are not “fearless.” They are courageous – but courage isn’t the absence of fear, only the mastery of it. Proper firearms training should strengthen a law enforcement officer’s ability to control their emotions and slow down the paralyzing physiological effects of fear on their bodies. This is critically important to law enforcement because violent confrontations can occur with little or no warning. Impulsivity or emotional reactivity has no place in law enforcement. Police recruits exhibiting aberrant behavior or an unfitness for the profession must be immediately identified and either retrained or removed from the field as soon as feasible.

And implicit biases – an attitude or stereotype that unconsciously shapes our understanding of a situation can affect every single one of us. For an agent of the state, furnished with arrest powers and a sidearm, an implicit bias can have a dangerous effect on a cop’s judgment, decisions, and potentially deadly actions. While we all may suffer from biases of this sort, cops must especially work hard to identify, acknowledge, and resist them.

Situational awareness. Law enforcement officers have considerations that go beyond neutralizing the immediate threat. For example, an officer must take in the entire scene in a split second when making the decision to shoot or not. Bodies aren’t bullet traps, and bullets don’t always expend all of their kinetic energy within the intended body they strike. Discharged rounds can also directly strike an unintended person. In short, every round a law enforcement officer discharges must be considered. The difference between one bullet and three may be the basis for an excessive use of force charge. In deciding to pull the trigger, a law enforcement officer must be able to assess how his action will affect everyone at the scene.

In short, the mental calculus that occurs in high-stress situations is one that requires cycling through a multitude of reactions and potential outcomes in a matter of seconds. The officer must then make a split decision, knowing that he will assuredly be second-guessed. The “reasonableness” standard for law enforcement is therefore more of a continuum that is highly dependent on the facts of the case, rather than a bright line.

Viewing Slager’s actions along this spectrum, he did not act “reasonably,” and here’s why:

No matter how much adrenaline that courses through a law enforcement’s professional’s body during a foot chase or a struggle, the minimum amount of force must be applied to take the subject into custody or neutralize his efforts to harm the cop or others. That is certainly a difficult exercise. Law enforcement must strive to deescalate situations when someone first seeks to turn the encounter into a contentious interaction with the potential to turn explosive.

And for those who have never been in a fight, or punched in the nose, the idea of focusing on de-escalation amidst the chaos can be an abstraction. The esoteric nature of “physical combat” with someone whom you may perceive to want to disarm you and use your weapon on you is difficult to appreciate for those who have never been in the arena. But that wasn’t what occurred in the North Charleston slaying.

There was no “struggle” ensuing when Walter Scott fled on foot. He was retreating, attempting to avoid being taken into custody. No threat. No reason to empty a weapon into his back.

The guilt in Slager’s case was confirmed by a damning cover-up attempt. The now convicted felon attempted to conceal the execution by planting evidence and lying about the details of the shooting to another responding cop. What Slager perpetrated and then attempted to pull off is exactly one of the worst-case scenarios that inner-city community members have feared for years. This, a classic case of police brutality resulting in a murder and then an attempted cover-up. But, in the immortal words of one-time Associate Supreme Court Justice Louis Brandeis, “sunlight (the cellphone video) is the best disinfectant.”

And despite his clear guilt, the 2016 state murder ended in a mistrial. Slager ultimately pleaded guilty to the federal charges last May, and U.S. District Court Judge David Norton handed down the sentence. After listening to several family members make painful emotional statements, while professing forgiveness for Slager, the judge pointed out that the “appropriate underlying offense” in the case brought against the ex-cop should have been second-degree murder.

Slager was certainly entitled to due process and his day in court. And he was afforded those rights—rights that he summarily denied Mr. Scott. The Scott family exhibited equanimity and grace under incomprehensible circumstances. Difficult though it must have been, in open court, they expressed their forgiveness for Slager. But, here, I’ll say it—the disgraced and defrocked cop should have been given a life sentence. Any “mitigating factors” and “extenuating circumstances” provided at trial honestly cannot soften the revolting videotaped images we all ingested.

A staggering number of young African-American men are murdered each year by folks who look just like them. The city of Chicago is a veritable “war zone,” and ended 2016 with 792 slayings. And while the president was lambasted for his inflammatory remarks at a rally in Pensacola, FL, on Friday evening, where he stated that Chicago was more dangerous than Afghanistan, as it relates to African-American men, he’s actually right about the painful numbers.

According to Niall McCarthy in a September 8, 2016 article for Forbes:

Since 2001, Chicago has experienced 7,916 murders (as of September 06, 2016). The number of Americans killed in the wars in Afghanistan and Iraq was 2,384 and 4,504 respectively since 2001.

This should be concerning to all of us. It is especially concerning for cops assigned to patrol tough inner-city neighborhoods in places like Chicago. Consider that when every shooting reflexively reinforces the notion that policing as a profession is “racist” and “predatory.” Law enforcement should not be viewed as the preeminent instrument of lethality to young men of color—and that’s often the message. This eclipses our ability to find any common ground to work in concert to address all forms of criminal violence.

But let’s acknowledge a clear distinction here. Law enforcement should be an institution all Americans look to for protection. Acting as an instrument of the state, under color of law, demands far different accountability than we expect of our citizens. And when an egregious officer-involved-shooting appears “sanctioned” by the state, it rattles the uneasy détente between law enforcement and communities of color.

Law enforcement is an inherently honest profession. The vast majority of those who are drawn to this type of dangerous public service just want to make a difference. They want to be that Thin Blue Line between their neighbors and those who might attempt to harm them. The pay is lousy. The hours are insufferably long. The dangers are abundant. But, sadly, much of our citizenry simply doesn’t respect the badge anymore – and cases like this one don’t help alter negative perceptions.

The policing profession is tough enough in this country without the considerable setback that Slager’s case has created for efforts to bridge the divide between law enforcement and the communities they serve.