Your post and the original post expressing regret about a 100,000 reward being offered for tips leading to the capture of that cop killer, led me to do a bit of research. We have long had the practice of offering such rewards. While there were some where the reward was paid dead or alive, they were to appeal to professional bounty hunters in an era where police were few and far between except in cities.

The Saint Louis Midland Rail Road offered 25,000 in gold for Jesse James dead or alive-that of course far more than the 100,000 reward being offered. Today, were you to shoot this lowlife, you would need to prove he represented a danger and you had no other choice.