If they unlawfully took a life, they should definitely have harsher penalties. Police officers are not above the law. They need to be held accountable just like everyone else. We are witnessing, at an alarming rate, police officers abusing their power. They need harsher penalties for a lot of things and not just taking lives.
If a police officer takes a life he should be punished as anyone else is. The problem is that they are being treated more lightly than other people, in some cases by not being indicted or charged at all.Once criminal charges are in place and if they are convicted they should face the same penalties.
Unfortunately taking lives is part of police work and while there should be more training on how cops should deal with difficult situations, I do not think that harsher penalties is the answer. If a perp is threatening the life of others or of the police officer then a cop should not have to second guess their actions in neutralizing the perp.
This is a very sensitive topic. The answer will really depend on the circumstances, and it is always hard to determine whose life is more important and should be preserved. It is also difficult to determine in which circumstances taking a life was actually necessary, and whether something could have been done to prevent it while also preserving innocent lives. Harsh penalties should be applied to unnecessary use of violence, but sometimes taking a life is necessary.