[tdrot]

1. Will it dissuade others from committing murder?

The way the US currently carries out the DP does not seem to be a deterient because the number executed is small and the time between conviction and execution is long. It might be somewhat different if all convicted murders were given the death penalty, the appeals process took only 1 year and the executions were public. Given that this kind of a change is not likely to happen I would then say this is not an argument for the DP.

2. Is there more than a micro chance that the life sentence will allow an eventual release or escape?

This could be a reasonable argument for the death penalty, but the number of people that are released from prison who have sentences of life without parole is small. Then the number of those that murder again is even smaller. So I would say that the number of innocent people this group kills would likely be offset by the number of innocent people that are wrongly convicted and put to death.

3. Does it cost more to keep him alive?

I will take at face value the information in other posts that these costs are roughly even.

4. Is there more than a micro chance that the defendent is innocent?

We could change the law to state that DP cases must have conclusive DNA evidence or they can be convicted but no DP.
If we don't than my argument in two would seem to offset this issue.

5. I think there might be one more argument which is a life in prison sentence gets the whole public and family ordeal out of the way quicker. As it stands now, every year and a half or so the case has an appeal that needs to be decided. The families of the victims are then reminded of the whole thing and this goes on for 15 to 20 years. I think with life in prison without parole the appeal process is over sooner and if the conviction stands the murderer is sent to live out his life in prison.

By the way, I am in favor of the death penalty purely on an emotional level.