Today is a crucial day in the Derek Chauvin Trial

Prosecutors just called their first medical expert witness: Martin Tobin, a pulmonologist working at Loyola University Medical Center

Expect him to testify that George Floyd did not die of an overdose

#ChauvinTrial

Tobin testifies that the combination of one of the officers pushing Floyd's handcuffs into his back, combined with Chauvin's knee on Floyd's *back*, made it so Floyd couldn't breathe out of his left lung

#ChauvinTrial

I don't necessarily think this is great testimony for the prosecution: they've spent almost the entire time saying that it was Chauvin's knee on Floyd's *neck* that was excessive force

This is fascinating testimony

Tobin is a very persuasive expert - he makes a lot of sense, is understandable

This will be a very, very difficult cross-examination

Whoa now it looks like the expert is getting out in front of his skis

He's saying from a picture that 86 pounds of weight is on Floyd's neck

That's not obvious at all, and it's not obvious that Tobin is speaking from expertise here

I agree - on the whole he's been one of the prosecution's best witnesses

That said there is still a mismatch between what the prosecutors have established was "excessive force" and cause of death https://twitter.com/RyanPrestage/status/1380183051171414019?s=20

Big thing I'm wondering is why the prosecution couldn't find a use of force expert with the experience level of this medical expert

Maybe all the experienced use-of-force experts thought the use-of-force was clearly justified?