Defense attorneys began their defense of a former U.S. Marine charged with fatally choking a homeless man aboard a Manhattan subway by calling the defendant's older sister to the witness stand.

This week, Daniel Penny was finally portrayed in court as a peaceful, compassionate man hardwired to intervene on behalf of strangers in peril.

Jordan Neeley’s death was a direct result of the chokehold Daniel Penny held him in, a medical examiner testified Friday, rebutting assertions from the defense team that the former Marine did not apply enough pressure to kill the subway rider and that his death could have had some other cause.