We would like you to assess the QUALITY of each of the following argument (discussing Death Penalty) and determine if the argument is Valid or Invalid. A valid argument is clearly interpretable and either expresses an argument, or a premise or a conclusion that can be used in an argument for the topic of death penalty. An invalid argument is a phrase that cannot be interpreted as an argument or not on the topic of death penalty.

And in an atheist's perspective, from our own morals, we should know that causing another death of a human being is highly unnecessary, considering that we all ready have them behind bars.
Valid

As long as we sentence people to a life in prison we are also GUARANTEED to sentence an innocent person.
Valid

how can a man or woman who has adjusted to the prison system just all of a sudden become a useful member of society?

Valid