Lawyers for Daniel Penny, who is accused of choking Jordan Neely to death, called an expert who argued that a combination of factors led to Mr. Neely’s death.

Daniel Penny has chosen not to testify at his trial in the death of an agitated man he choked on a subway train.

Daniel Penny’s defense team called an expert witness Thursday, who challenged the medical examiner’s determination that Jordan Neely died as a result of the former Marine choking him on a subway car.