I am not a gun owner, and generally am opposed to gun ownership, but...
The fuss about the victim being armed while on the streets appears to me to be the first step in the confiscation of firearms in private hands.
It wasn't that he was armed on the streets, this is such an equivocation, omitting facts to conform to a narrative, it's that he was irresponsible.
He obstructed an officer of the law without saying he was armed, with a concealed weapon. The subduing of Pretti was going as many of these interaction do, him struggling and resisting. Officers then discovered the concealed weapon, yelled "GUN", removed it from the struggle. Were there more weapons? Who knew at that time? Only Pretti knew. Until Pretti is subdued and searched only can they then declare "CLEAR".
Then things get strange, either the weapon accidentally discharged (twitchy trigger on SIG pistols) as the officer was walking away with the weapon or when Pretti in his struggle, got on his knee and reached to his back where the weapon was previously holstered was then shot (famous photo TruthNLies posted). The officers reacted, knowing the suspect had/has a gun.
The investigation will determine the timing of the events, I believe when he reached to his back hip, the first shot had just rung out, but the videos/audio are too jumpy to make a solid determination. Ergo IMO the weapon had an accidental discharge, and the other officers reacted to the sound (first shot, then tiny pause, then multiple shots are fired).
Tragic, all because a person brought a concealed weapon to a protest, which is his right, but doesn't absolve someone from being irresponsible.