A former Marine combat instructor testified that Daniel Penny misused a combat maneuver when he fatally choked Jordan Neely aboard a Manhattan subway, saying he appeared to have attempted a “blood choke” and should’ve known to let go after Neely lost consciousness.

Penny held Neely in a chokehold for about six minutes — including for more than 50 seconds after Neely stopped moving — according to evidence presented in his criminal trial.