At the time, I felt just the same way about Mark David Chapman as you do. But that's no excuse for taking revenge. The test of compassion is whether you can apply it to the unattractive as well as those who are easy to empathise with.
There are very few peole who kill for either pleasure or reward. Most killers are at least temporarily unbalanced. Make no mistake, John Lennon opposed the death penalty. It has gone from all civilised countries in the world. We don't miss it. Peace for me means peace between all men. I find it hard to take that some of the most brutal killers of Northern Ireland are walking around scot free, but that was the price we had to pay for peace. It doesn't come cheap, but it's worth it.
Mental illness really does exist, I am afraid. Mentally ill people can be boring, time consuming and downright aggressive. They deserve as much compassion as any other sick people. My life has brought me into a lot of contact with the mentally ill. It is not always easy to see the good in them, but I do not believe we have the right to exclude them from society unless they represent a real and present danger. I do not believe that is true of Lennon's killer any more. I detest the deed itself, but the man deserves a chance of freedom.
The word "peace" can slip from our tongues very glibly. It is actually very hard to achieve and maintain.
Peace.