One out of every 7 of the nationâs prison inmates is serving a life sentence, according to a report by The Sentencing Project. For Blacks, the proportion of lifers is in 1 in 5. Despite a growing consensus for prison reform, âWe see life sentences continue to accumulate,â said senior research analyst, Ashley Nellis. Most people âage out of bad behaviorâ in their 20s and 30s, âso incarcerating them for decades past that point serves no public safety benefit,â she said.