The incident had the hallmarks of an execution. Harris County Deputy Darren Goforth was filling up his patrol car at a suburban Houston gas station Friday when a man he had never met walked up behind him and opened fire, police say.
The suspect, Shannon Miles, is in custody but "we have not been able to extract any details regarding a motive at this point," said Harris County Sheriff Ron Hickman.
In struggling with the overwhelming senselessness of the loss, Sheriff Hickman turned to what, for the nation at large, has become a familiar topic.
“We’ve heard black lives matter, all lives matter,” he said at a press conference. “Well, cops’ lives matter, too.”
The anti-police rhetoric surrounding the Black Lives Matter movement, he added, has ramped up “to the point where calculated, cold-blooded assassination of police officers happens.”
In the aftermath of such tragedy, it is perhaps an understandable sentiment. The comment came on the same day that a group of Black Lives Matter protesters in Minnesota appeared to chant offensive anti-police slogans. And it echoed the comments of a police union official last December when two New York City police officers were ambushed and killed by someone who had participated in Black Lives Matter protests. There was "blood on the hands" of the mayor for standing with protesters, not cops, police union chief Pat Lynch said at the time.
Beneath such comments is the implication that the fallout from the last year's protests, which arose in Ferguson, Mo., has made police beats more deadly. But are fatal vigilante attacks against police on the rise post-Ferguson?
So far, data don't dismiss the idea, but nor do they show strong evidence supporting it. Though there was a jump in the number of police killed in so-called ambush attacks last year, it was within recent norms. And while the numbers for police killed in ambushes this year are not available, the overall number of police killed by guns is down and near historic lows.
Instead, Hickman's comments appear to point more to a broader challenge to morale in police departments nationwide. Public confidence in police has fallen to a 22-year low, according to Gallup, and that has left departments from Baltimore to Virginia Beach, Va., feeling "under siege."
"When you see officers in Baltimore going through what they're going through – and in Ferguson and New York – that affects morale here," Brian Luciano, president of the Virginia Beach Police Benevolent Association, told The Virginian-Pilot. "You just see your brothers and sisters, and that could be you."
Some officers have said that they see more belligerence in those they stop on the street. But there is not yet strong evidence to support what Harris County District Attorney Devon Anderson said she worried was an "open warfare declared on law enforcement."
Last year saw a spike in overall police deaths by gunfire (51). But 2013 had marked a 33-year low (27), and data for this year suggest a return to pre-2014 levels, with 23 officers killed by gunfire as of Aug. 30.
The number of police killed last year in ambush attacks also tripled to 15, according to a report by the National Law Enforcement Officers Memorial Fund. But 15 officers were also killed in ambush attacks in 2009, 2010, and 2011, CNN reports. Police ambushes can be connected to a variety of causes.
Last year, for example, an antigovernment sniper made headlines when he killed an officer at a Pennsylvania police barracks in September, and two policemen were shot point-blank last June while eating at a Las Vegas pizzeria by a couple trying to start a "revolution."
For their part, many Black Lives Matter activists say they want peaceful police reform. And they rejected the claim that their movement led to the officer's murder.
"It is sad that some have chosen to politicize this tragedy by falsely attributing the officer's death to a movement seeking to end violence," DeRay Mckesson, a leader in the movement, tweeted. "I do not condone killing," he added.
And for some police officials, the rising concern is less about personal safety than running afoul of society's changing expectations for policing.
"Police are under siege in every quarter," said Gene Ryan, president of Baltimore's Fraternal Order of Police Lodge 3, in a statement. "They are more afraid of going to jail for doing their jobs properly than they are of getting shot on duty."
Studies have found that police cope with the operational stress of doing their jobs far better than they do with organizational stress.
On Saturday, hundreds of Houston residents showed up at the Chevron station where Mr. Goforth was killed to offer support for police officers amid trying times.
Carol Hayes, an African-American woman who attended the vigil, told NBC News that her family had always felt welcome in the area. "I wanted to demonstrate that all lives matter, regardless of color," she said.