Fentanyl, meth, morphine, and pot.
Supports my early guess the guy was going to die of an overdose within a few minutes anyway. Viable argument that asphyxiation was an OD consequence (couldn’t instinctively struggle for air, apparently a common fentanyl OD mechanism).
Also supports the store employees saying his was high on something. If the cops had been delayed getting there, he’d have been dead and all these riots would have been delayed a couple weeks until they had some other made up excuse.