Why did police wrongly claim that Sicknick died of injuries in Capitol riot?

Washington Examiner: A top GOP senator is demanding to know why the U.S. Capitol Police claimed Officer Brian Sicknick suffered mortal injuries while on duty and after clashing with protesters during the Capitol riot in light of the District of Columbia’s chief medical examiner’s ruling that Sicknick died of natural causes.

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Someone allegedly with the police gave the NY Times the false narrative about his death.  When the fire extinguisher story was extinguished someone with the police said he was attacked with “bear spray” That story was not true either.  I get the impression that there was political pressure on the police to concoct a story that would play into their narrative about the rioters being violent in attacks on police.  Johnson is right to try to discover who was behind these bogus reports.

Source: Why did police wrongly claim that Sicknick died of injuries in Capitol riot?