US President urges more progress on criminal justice reform

In the 56-page article, the president defends his government's actions during his eight-year term on a subject that was crucial for him before his arrival at the White House.

And he also a calls on President-elect Donald Trump -- who is not mentioned in the article -- to urgently pursue further reforms.

"We simply cannot afford to spend $80 billion annually on incarceration, to write off the seventy million Americans... with some form of criminal record, to release 600,000 inmates each year without a better program to reintegrate them into society, or to ignore the humanity of 2.2 million men and women currently in US jails and prisons," Obama wrote.

The article, titled "The President's Role in Advancing Criminal Justice Reform," comes less than three weeks before Trump's January 20 inauguration.

Obama, a former constitutional law professor, earned his law degree from Harvard University. He was the first African American president of the prestigious Harvard Law Review, a student-run law journal that publishes eight regular annual issues.

In the article, Obama talks about the reforms he would have liked to have been able to make more progress on, such as tightening gun control laws on individuals.

"There should be no mistake that gun violence is an epidemic playing out across the country every day," he wrote.

"Over the past decade alone, more than 100,000 people have been killed as a result of gun violence -- and millions more have been victims of assaults, robberies, and other crimes involving a gun."

Over the same period, he said, "nearly 200,000 of our neighbors, friends, and family have committed suicide with a gun."

The president also emphasized the problem of overpopulated prisons, estimated at 2.2 million people currently compared with less than half a million inmates in 1980.

Obama said he favored alternative punishments for small crimes. In recent months he commuted the sentences of hundreds of prisoners, most of them in jail for drug-related offenses.

"More than six million American -- disproportionately people of color -- cannot vote because of a felony conviction that disenfranchises them," he wrote.