. (Photo by Christian K. Lee/The Washington Post)

Three police officers were targeted and shot in three apparently unrelated ambush attacks in a 12-hour span on Sunday. One of those officers, Benjamin Marconi of San Antonio, Texas, was killed by his assailant, who remains at large.

Marconi's death is the latest example of what law enforcement advocates call a disturbing spike in ambush attacks on officers this year. The 20-year veteran of the San Antonio police department was the 20th police officer killed in an ambush this year. With more than a month still to go in 2016, the number of fatal ambush attacks on officers this year already exceeds the number in any of the past 10 years, according to data from the National Law Enforcement Officers Memorial Fund, an organization that tracks police fatalities.

According to the International Association of Chiefs of Police (IACP), four factors typically define an ambush attack:

  • An element of surprise;
  • Assailants who conceal themselves, their weapons or their intents;
  • The suddenness of the attack;
  • A lack of provocation.

Attackers may attempt to lure lone officers into a situation with the intent of killing or injuring them in a pre-meditated attack. But more often, the assaults are spontaneous -- the result of an attacker taking advantage of an unexpected encounter with an officer.

The killing of Marconi appears to fall into this latter category. He was shot in the head while he sat in his patrol car while writing up a traffic ticket for a motorist evidently unconnected to the attacker.

Like many categories of crime, ambushes on officers have become rarer since the early 1990s. In 1991, for instance, there were more than 500 ambush attacks (fatal and non-fatal) on officers. By 2015, that number had fallen to 240 assaults, according to official FBI statistics.

Overall, killings of police officers are down too, according to the FBI. In 2011, for instance, 72 officers were feloniously killed in the line of duty. By 2015, that number had fallen to 41.

This year is shaping up to be a more violent year for officers than 2015. Overall, officer fatalities from all causes including accidents are up 16 percent from last year, according to the National Law Enforcement Officers Memorial Fund. But the number of officers fatally shot by suspects is up by 67 percent year over year.

These figures are subject to significant year-over-year fluctuation in part because these incidents are so rare. When only 10 or 20 incidents happen in a given year, as with ambush killings, it's easy for one or two outliers to drastically affect the numbers.

Zooming out to the larger picture, policing during the Obama administration remains safer than it has been under any recent presidential administration. Since the early 1990s, for instance, violent crime has plummeted. Motor vehicles have become much safer. States have passed laws making the roadways safer for police.

All of these factors, and their myriad causes, are a much bigger driver of officer safety than the policies of whoever's sitting in the White House. That's been true during the Obama administration, and it will be true during the Trump administration, as well.

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