The only other year with fewer deaths in the past five decades was 2013, when 116 officers were killed. 

These deaths should not all be interpreted as the result of attacks from members of the public. Traffic accidents are the leading cause of police-officer deaths, although shootings play a significant role. 

Although we continue to hear complaints about a "war on cops" from police labor unions, government institutions, and their allies, there is no evidence to support the claim. 

As Tate Fegley noted in October, the most recent data continues a decades-long trend:

[T]here has been a downward trend in officer deaths over the last few decades. In 2016, the number of police officers killed by gunfire was less than half of what it was in the early seventies. Contrary to the narrative of there being a war on cops, rather than a series of isolated incidents of violence against police officers, the number of officers being killed is going down while the number of people employed as police officers goes up.