PHILADELPHIA >> A jury cleared an Amtrak engineer today of all charges stemming from a derailment that left eight people dead and hundreds injured in Philadelphia in 2015, concluding that his operation of the train at more than twice the speed limit on a curve didn’t constitute criminal negligence.

The jury took just over an hour to acquit Brandon Bostian, 38, of causing a catastrophe, involuntary manslaughter and reckless endangerment — one count for each injury and death. Amtrak had earlier settled civil litigation over the crash for $265 million.

The train rounded a curve at about 106 mph, more than twice the speed limit, before it derailed in north Philadelphia.

Bostian’s lawyer described him as a lifelong train buff who had a perfect work record until he was distracted by people throwing rocks in the area just before the crash. He could have been sent to prison for years, or even for life, if convicted, given the high number of counts against him.

“It’s been seven years for him wondering if he’ll ever get his life back. Today the jury gave him his life back,” defense lawyer Brian McMonagle said after the verdict. “We’ve been saying from the beginning there was never a crime committed here by Brandon.”

In closing arguments, McMonagle said the criminal actors in the case were those who threw the rocks at the train ahead. They were never apprehended.

Federal safety investigators concluded that Bostian lost what they call “situational awareness” on the track, thinking he was past an S-curve and on a straightaway when he accelerated from about 65 mph to 106 mph. In fact, he was in the middle of the S-curve and going more than twice the 50 mph speed limit. Investigators found no evidence he was impaired, fatigued or using his cellphone at the time.

The key question for the jury was whether Bostian — who no longer works for Amtrak — sped up intentionally, knowing the risks — the threshold required for criminal negligence.

The case has a long legal history, with judges debating whether Bostian’s actions constituted a crime. Common Pleas Judge Barbara McDermott, who presided at the seven-day trial, questioned whether the evidence was enough but said she would consider the issue after taking a jury verdict. The point now appears moot.

Prosecutors say Bostian acted with reckless disregard for the safety of his passengers, who were traveling from Washington to New York that Tuesday evening. The train had stopped at Philadelphia’s 30th Street station about 10 minutes earlier and was heading north.

“There is no question that the excessive speed of the train that the defendant operated resulted in death and injury to his passengers,” the state Attorney General’s Office said in a statement, adding that it pursued the case to seek justice for victims and their families. “Ultimately, the jury did not find his actions to be criminal, and we respect the jury’s verdict.”

A year later, Amtrak settled lawsuits over the crash for $265 million, a new, higher limit set by Congress after the crash.

Philadelphia’s top prosecutor declined to pursue criminal charges. The Attorney General’s Office later took the case to trial, after some victims’ families pressed for charges.

The jury had begun weighing the charges this morning when the judge announced around noon that an alternate would step in because one juror had experienced a death in the family. The jury then began its deliberations from the start.