Holder declared the current system "broken" and "far from sustainable," in a speech in San Francisco to the American Bar Association.
Holder cited the soaring prison population, which since 1980 has increased 800 per cent while US population increased only by about one-third. He emphasized studies such as one that showed black male offenders receive sentences nearly 20 per cent longer than white males convicted of similar crimes.
"This isn't just unacceptable - it is shameful," Holder said.