Well, no. A murder didn't used to be something extraordinary. Especially not in Germany---with respect, we are still talking about the country that committed genocide as state policy in the '40s. Germany's murder rate has remained basically flat for decades [
https://ourworldindata.org/homicides]. What has changed is the population has risen by about 10 million in 50 years, so with a flat rate, you're going to see more murders.
...but more importantly, what has also changed extraordinarily is communication. We see a lot more of the murders, be they local, national, or international (the fact that we, a German and an American, are discussing Australian policy in response to a New Zealand murder spree is indicative of this). Internationally, we're a lot less tolerant of murder than we were because we can see it now. And as a species, we're pretty bad at risk assessment and filtering with this newfound panopticon power. It's a pretty well-documented phenomenon that fear in Germany of crime doesn't align with the hard numbers on incidents. https://www.bloomberg.com/opinion/articles/2018-05-09/german...
People see what they expect to see all too often.
If I may make an observation... You appear to be ascribing to some conspiracy-theory thinking in the statement that the coroner report aligned with perceived political pressure. Where is that notion coming from?