How did the cited studies try to argue causality?
In other words, it is expected that certain behaviour (drug use, “criminal lifestyle”) both causes time spent in prison and lowered life expectancy. Just correlating time spent in prison and life expectancy does not cut the cake.
You would need some kind of randomized control group. For example: Suppose the judges responsible for granting parole were assigned on a last-name basis. Different judges have different statistics on granting parole. Then you compare life-expectancy vs last name of delinquents.