ALBEMARLE COUNTY, Va. (WVIR) - Federal investigators are now pointing to marijuana and anti-seizure medicine as the likely cause of a deadly train crash in Crozet last year.

The National Transportation Safety Board (NTSB) released its final report Thursday, March 21. The board believes Dana William Naylor Junior was likely under the influence when he drove a Time Disposal trash truck around the crossing arms on Lanetown Road and onto the train tracks back on January 31, 2018. An Amtrak train carrying congressional leaders struck the vehicle, seriously injuring Dennis James Patrick Eddy and killing 28-year-old Christopher Sachem Foley. There were some injuries on the, train too.

Naylor was charged with involuntary manslaughter and DUI maiming.

The DUI charge was dropped once Judge Cheryl Higgins threw out Naylor's blood test - which indicated levels of THC in the defendant's system- saying it didn't mean he was impaired at the time of the crash.

“The jury did not receive evidence that the THC level in his blood was 6.6 milliliters per nannogram, which is a substantially high level, and one that would have created a presumptive level of intoxication in other states," said Albemarle County Commonwealth’s Attorney Robert Tracci.

Judge Higgins said that since there isn't a set standard on THC and impairment, she would not allow the jury to see the results.

Naylor was found not guilty of involuntary manslaughter by a jury. He still faces several civil suits from train passengers and victims of the crash.

NBC29 reached out to Naylor's attorney for comment.