Sicknick died of a stroke the next day, apparently of natural causes. There are claims (originally presented by all media channels as foregone conclusions) that he was beat in the head with an extinguisher the day before, but the medical examiner’s report doesn’t corroborate that.

https://www.snopes.com/fact-check/brian-sicknick-fire-exting...

Edit: used a hopefully unbiased source that includes criticism of both the right- and left-leaning media’s coverage.

From Wikipedia:

> Five people died either shortly before, during, or following the event: one was shot by Capitol Police, another died of a drug overdose, and three succumbed to natural causes

Please cite your sources, in particularly for the "a cop was murdered", or please stop spreading lies and misinformation.

Nobody was killed by any of the rioters.