A major shake-up in the White House as President Trump returns to Washington DC from an appearance on Long Island. Reince Priebus is out as chief of staff and Homeland Security Secretary, General John Kelly, is taking his place. Our Grace Rauh has the story.

A dramatic change in the White House. Reince Priebus — the President's chief of staff — is gone and a retired four-star Marine general is taking his place. The president announced the change on Twitter, before talking to reporters about his new chief of staff, John Kelly, on the tarmac outside Air Force One.

"Reince is a good man. John Kelly will do a fantastic job," President Trump said. "General Kelly has been a star, done an incredible job thus far, respected by everybody. He's a great, great American. Reince Priebus a good man."

Priebus has been marginalized for some time within the West Wing. Earlier this week the White House Communications Director Anthony Scaramuchi openly disparaged Priebus in a profanity-filled rant and said he'd be forced to resign for his alleged leaks.

"The president has a right to change direction," Priebus said. "The president has a right to hit a reset button. I think it's a good time to hit the reset button."

Earlier, President Trump appeared at Suffolk County Community College on Long Island to take aim at MS-13, the violent gang beleived to be responsible for 17 deaths in the county over the last year and a half.

He also urged police to rough up criminal suspects.

"I said 'please don’t be too nice.' Like when you guys put somebody in the car and you’re protecting their head, you know. The way you put their hand. Like don’t hit their head and they’ve just killed somebody. Don’t hit their head. I said 'you can take the hand away, ok?'"

The president did not mention Mayor Bill de Blasio by name — but he attacked him in his speech. "I've met police who aren't allowed to do their job because they have a pathetic mayor," Trump said. "Or a mayor who doens't know what's going on."

The mayor wasted little time responding — his campaign sent out this fundraising email explaining the the President had attacked de Blasio and was determined to keep him from winning re-election.