Two major changes have been the increase in speed and breadth of information access. We simply know about more crime, from a wider area, than we ever have before. When all you knew about was your local community, crime would often be seen as very rare.
It wasn't long ago that millions could die in war or famine that most of the rest of the world knew nothing about. Now, a single death can be global news in seconds.
So, just because some bad stuff happened somewhere is not necessarily proof that the world has gone to hell in a hand basket. Reducing the sensationalist elements of death, crime and war might be an idea, but has its drawbacks. Education - to understand what you are being told - is probably the key but who knows if that would ever be possible.
The second major change has been the increase in the capability to kill large numbers of people in a short space of time.
A lot of this is the by-product of technological development. You will never control it all, but you can make items difficult to access. Its that, or we all go back to living in the trees.