TL;DR … Trump is a lying fraud repeating an endless list of fraudulent horror stories and blood libels meant to induce fear and desire for revenge. The rising police death toll claim is another one of these …
Per the Trump lie factory, the Washington Post notes that these are the average number of police fatalities per year from all forms of attack broken down by presidency …
Reagan 101
Bush 90
Clinton 81
Bush 72
Obama 62
This trend of course has little if anything to do with President Obama. It is a clear trend going back decades and must at least partially map to declining crime rates over all, though it decade begin while crime rates were still rising.
Changing population and changing numbers of police over 36 years obviously make the trend a little murkier, though a growing society would likely lead to more deaths in absolute terms. In any case, point being Trump’s claims about a hunting season on police under the Obama presidency are another instance of demonstrable lies intended to incite fear and hunger for revenge. We’re basically to the TL;DR phase of the storyline. But there you are.