He was taken to a hospital, where he died at 9:30 p.m. Thursday, police said.

According to sources familiar with the matter, authorities believe Sicknick's death was driven by a medical condition. They're also investigating reports that he was attacked with a fire extinguisher or another item at the Capitol, sources said. So far, reports of an attack haven't been confirmed and authorities are hoping to locate video or other imagery from the scene.

Sicknick's family said in a statement, "Many details regarding Wednesday's events and the direct causes of Brian's injuries remain unknown and our family asks the public and the press to respect our wishes in not making Brian's passing a political issue."

But look at the HEADLINE:

Federal murder probe opened for Capitol Police officer Brian Sicknick who died following riots