After the Supreme Court effectively legalised gay marriage and voted to preserve a key aspect of Obamacare, Barack Obama hinted that he would make criminal justice reform the focus of the last months of his presidency.

The White House has now announced that next week Obama will become the first sitting president to ever visit a federal prison, when he travels to El Reno Correctional Institution in Oklahoma.

At the prison Obama will be interviewed by Vice for a documentary on prison reform due to air later this year.

According to the New York Times, Obama plans to commute the sentences of dozens of non-violent drug offenders at federal prisons before he leaves office.