Balog,
The nightstick or baton is a tool that has many uses. One doesn't just swat someone in the head with it. It can be applied to certain areas of the body such as face, neck, arms, hands, shoulders, collar bone, ribs, solar plexus, shins and used to tangle up the feet of someone attempting to flee. It's like any tool, one needs to know what it's capabilities are and then train in their use. If used in places other than the head, use of it is non fatal for sure.
With the taser, death can result at any time and has shown itself to be rather ineffective as noted by the use of multiple shocks. A mentally unstable and violent young man was killed just a couple days ago in East Grand Rapids, here in West Michigan. He was tased 4 times by two rather substantially sized police officers.
Sometimes police officers get a fat lip or two, some scrapes and bruises and torn clothes in the line of duty. It's part of the job. So the taser is employed rather than using physical force with either no effect or catastrophic effect. It's use has become one of convenience sometimes/oftentimes? rather than necessity as I mentioned in my earlier post.