What we do know is that Trump blocked the National Guard from being deployed for several hours, until apparently Pence okayed it. The capitol police would normally coordinate with other federal law enforcement groups, but that wasn’t done. This was definitely not a case of feeling the security wasn’t needed - the police didn’t follow standard procedures for dealing with a crowd of this size, much less one that had publicly discussed storming the capitol building and being violent. They made no effort to establish a proper cordon and contain the crowds where they needed to be stopped. The cops aided the rioters (opening barriers to let them inside what should have been a cordoned area, posing for selfies, telling them where offices were so they could vandalize them…). The rioters also included actual police officers.
So really, the only question is whether Trump directly coordinated, directly or indirectly, with the police or just blocked the use of federal forces and capitol police independently, knowing what was going to happen and sympathetic to Trump, deliberately allowed it to happen. Because it sure as hell wasn’t just incompetence.
No, not the actual capitol police (but he does over other federal police, e.g. park police, that should have also been there), but he wouldn’t have to - whatever happened with the capitol police, it wasn’t the result of following (lawful) orders.
She specifically was asking that unidentifiable federal LEOs not be on the streets that would be indistinguishable from the militarized Trump fans, to avoid that sort of chaos.
She foresaw chaos and did request that the situation be treated seriously, and that the National Guard be deployed (which they really weren’t - what ended up on the streets was an insignificantly tiny force). But instead what happened was not just that it wasn’t treated seriously, but that the kinds of forces that normally would be deployed for a normal event of this size simply weren’t. Failing to treat the event seriously enough would be one thing, but this was a level of negligence that has to be deliberate to some degree, and not just on the level of the individual cops seen aiding rioters.
When foreign police in charge of capitol security with identical training and familiarity with procedures say, “The police deliberately botched their response” I’m leaning towards believing them.
That’s not really credible, though, as storming the capitol building was being publicly discussed ahead of time, by quite a lot of people. (Apparently including police, who were there as rioters.) It wasn’t a spontaneous thing, it was discussed and planned. Even if the cops had simply written that off as hot air - despite the history of violence of the group in question - they knew the crowd was going to walk to the capitol building. The capitol police failed to have even a basic cordon around the building, so they couldn’t really stop anyone from getting through. That practically functioned as an invitation to breach the capitol.