David A. Clarke Jr., the sheriff of Milwaukee County, was back in the news last week after announcing that he had been appointed to the Department of Homeland Security. (The Trump administration itself has not confirmed the appointment.)

Over the weekend, a CNN report accused him of plagiarizing parts of his 2013 master’s thesis, a charge that he has denied.

Sheriff Clarke has become a controversial figure because of the treatment of prisoners at the Milwaukee County Jail he supervises, his rhetoric regarding gun rights and criminal justice and his excoriation of the Black Lives Matter movement.

Here’s a quick look at the sheriff’s moments in the spotlight.

Who Is David A. Clarke Jr.?

Sheriff Clarke, 60, joined the Milwaukee Police Department in 1978 and has been the Milwaukee County sheriff since 2002. He was appointed to the post by the state’s Republican governor, Scott McCallum, and has since been re-elected four times as a Democrat, most recently in 2014. He has risen to prominence in recent years as a supporter of Donald J. Trump and as a conservative commentator on Fox News and Glenn Beck’s radio network.