The other three deaths happened on Jan 6th. At least one of them fully on Capitol grounds (the overdose, though she was in the middle of the crowd attacking officers at the "tunnel"). As I recall the other two were older men (50+) and one had a heart attack, the other might have been a fall, but I don't really know. Don't know if they made it to a hospital, but they didn't make it to Jan 7.
At the end of the day on Jan 6th there were 4 dead rioters (1 shot, 1 overdose, 2 older men) and several cops (and perhaps rioters) in serious conditions at hospitals. That's what was clearly reported (though the "overdose" and "older men" parts may have been vague given that autopsies hadn't been performed and kin notification policies).
The confusion that existed about the injuries and death of Brian Sicknick in the weeks that followed were just that "confusion". They do not alter what happened, nor excuse Tucker's attempt to whitewash the attack on the Capitol.