Daniel Penny's martial arts instructor from the Marine Corps took the stand Thursday for day six of witness testimony in Penny's trial in the chokehold death of Jordan Neely.

( NewsNation) — In the trial of Daniel Penny, a man accused of killing a homeless and mentally ill man on the New York City subway, jurors are hearing from experts on chokeholds following an admission from a key witness that he lied to police.

The homicide detective who interviewed Daniel Penny shortly after he placed Jordan Neely in a chokehold last year knew that Neely had died, he testified at Penny’s criminal trial Thursday. But Penny, he said, did not. Detective Brian McCarthy said he and his partner interviewed Penny while prosecutors watched secretly behind a one-way mirror.