Many of the victims’ families had been pressing for charges against Mr. Bostian — whose train when it entered a curve with a 50 m.p.h. speed limit — took action on their own.
First, on Wednesday, lawyers for 32 victims asked the district attorney’s office to accept a criminal complaint filed by the family of a woman killed in the crash, . The district attorney’s office declined.
Lawyers for some victims’ families, using the Pennsylvania law, filed criminal complaints with the Philadelphia Municipal Court requesting that charges be brought against Mr. Bostian. On Thursday, Judge Marsha H. Neifield accepted the complaints and ordered the district attorney’s office to reverse its decision and charge Mr. Bostian with involuntary manslaughter and reckless endangerment, .
But the district attorney’s office claimed it had a conflict of interest because it had already decided against pressing charges, so the office referred the case to the state attorney general.
Northeast Regional Train 188 was traveling to New York from Washington on May 12, 2015, when it derailed in the Port Richmond neighborhood of Philadelphia.
Investigators said Mr. Bostian and was not under the influence of drugs or alcohol, and his lawyer has said he has no recollection of the events leading to the derailment. The train carried 258 people, including eight employees.
knowledge of the train’s location, when he was distracted by radio transmissions from a nearby train that had been hit by a rock.
To charge someone with criminal recklessness, prosecutors would have to prove that a person “consciously disregards a substantial and unjustifiable risk,” the office said.
In deciding not to take action, the district attorney’s office said, “We have no evidence that the engineer acted with criminal ‘intent’ or criminal ‘knowledge’ within the special meaning of those terms under Pennsylvania law for purposes of criminal charges.”
“Nor do we believe there is sufficient evidence to prove, beyond a reasonable doubt, criminal recklessness, which would be the only other basis for criminal liability,” it continued.
A lawyer representing Mr. Bostian did not immediately return an email seeking comment. Thomas R. Kline, a lawyer representing some of the victims’ families and who led the team of plaintiffs’ lawyers who reached a settlement with Amtrak, did not immediately return a request for comment.
Friends of the engineer have said that, since he was a boy, Mr. Bostian , posting pictures of them on his bedroom wall. Colleagues considered him a dedicated employee.
Investigators said if the area of the derailment had been equipped with positive train control, a system Amtrak has since installed on tracks it owns between Washington and New York City.
Amtrak has to more than 100 victims and their families in a settlement.