I disagree—the point estimate for the increase in murders is well above 0 for the entire time period [figure 6]. The effect possibly fades away a little over time, so the confidence interval extends slightly over zero, but that doesn’t mean you can assume it is zero! If you did a statistical test for ‘did the increase in killings reduce over time’ you would not get a significant result.
Red is for murder and blue is for property crime, right?
Even if it’s still above at year 4 , that’s as far as the analysis warrants a conclusion for, and 4 years is still the short-term. You could specify “in the 4 years following the first protest” (although does this figure include police killings?). Your title reads to me as saying the rate will settle higher than without the protests or at least the drop in police killings will never make up for the increase in other murders, neither of which follow, and looking at that figure, neither seems more likely than not. How I read the title, it does’t even seem more likely to be true than false.