The man who attempted to kill FDR in February 1933 and caused the death of Anton Cermak, the mayor of Chicago, instead, was executed within a month or two of Cermak's death. If Lee Harvey Oswald had not been silenced by Jack Ruby and had been found guilty and sentenced to death, he probably would have died of old age in prison.
A fair and speedy trial and speedy execution would do wonders for those who wish to assassinate Police Officers.
Doesn’t change my hopes