Remember how Moe went in the ambulance with Anna but we didn't know where HKS was? Maybe he was asked to "stick around" and be interrogated by the cops at that time.
Moe said that HKS showed up later on at the hospital and KE says that HKS got to "spend some time" with her body that evening.
Have no idea when any of this would've been - especially without him leaving his hotel room for however many hours his sister said it was, 2-3 days or something, lol.