Shooting deaths of police officers in the US are on the rise this year. It’s a disturbing trend in itself, but perhaps more disturbing is the most common manner in which these officers were shot: ambushes.

So far this year, 14 police officers have been killed in ambushes, and while that number may seem low, it represents a more than 45% increase over 2015 [see update below], when only three officers were slain in ambush attacks, according to the National Law Enforcement Officers Memorial Fund…

The shootings have spanned the nation, from California to Massachusetts, and they’ve almost equaled the number of firearms-related police deaths in all of 2015. According to the fund, firearms were responsible for 41 of 123 officer fatalities in 2015. The number is 38 as of August 14 of this year. The decade’s highest total came in 2011, with 73 officers shot dead.

CNN then lists all 38 officers who have been killed this year along with a description of the circumstances in which they died. Notable this year are the two incidents in which multiple officers were killed by someone who said they were upset about officer involved shootings of black men.

Last month 5 were killed in an attack in Dallas which coincided with a march against police brutality. The shooter, Micah Johnson, told police he was angry about police shootings of black men and wanted to kill as many white police officers as possible.

Ten days after the shooting in Dallas, Gavin Long shot six officers in Baton Rouge, Louisiana, three of whom died. Long was a black separatist who believed bloodshed was the path to change. From the LA Times:

Throughout his postings on social media, Long described violence as the solution to what he saw as oppression of black Americans.

“One hundred percent of revolutions, of victims fighting their oppressors, from victims fighting their bullies, 100% have been successful through fighting back through bloodshed,” he says in one video.

The overall numbers of officers killed in the line of duty (including shootings) hit a low in 2013.

Update: A commenter points out that CNN’s math is off (and I didn’t catch it). If there were 3 ambush shootings of officers last year and 14 this year then the number is up by more than 367%. Technically, that is more than 45% but it seems CNN made a mistake. I put in a call to the National Law Enforcement Officers Memorial Fund and their spokesman just confirmed the figures CNN used are correct and also that their math was off.