Acevedo is leaving the 5,400-person department in Houston -- the fourth-largest in the country which he's led since 2016 -- to run the 1,400-person department in Miami and is its fifth police chief in the last decade.
Over the past year, the 56-year-old Acevedo - who is a registered Republican - has drawn national spotlight for marching with protestors after the death of George Floyd and spoke out against Trump while speaking at the Democratic National Convention.
"You better have a warrior's heart because there's a lot of evil people and evil doers in this world," Acevedo said. "We have to have a mindset of a guardian, but when those shots start being fired, we need to have the heart of a warrior."