The driver involved in actor Treat Williams' fatal motorcycle crash has pleaded not guilty.

Ryan Koss, 35, could be sentenced to up to 15 years in prison if he's convicted of gross negligent operation with death resulting. The driver was charged in August.

An investigation of the June 12 crash in Dorset, Vermont, concluded a vehicle pulled in front of Williams, who was riding a motorcycle and was unable to avoid a collision, Vermont State Police said.

TREAT WILLIAMS' DAUGHTER MOURNS HER LATE DAD ONE MONTH AFTER HIS DEATH: ‘KEEP FORGETTING HE’S NOT COMING HOME'

Treat Williams attends a special screening

A driver involved in the fatal crash that took Treat Williams' life has pleaded not guilty to a charge connected to the accident. (Lars Niki/Getty Images for the Academy of Motion Picture Arts & Sciences)

Koss was charged with grossly negligent operation resulting in death after he attempted to make a left turn in his Honda SUV and collided with Williams on his motorcycle, according to police. Williams was thrown from his motorcycle during the crash and was pronounced dead at Albany Medical Center in New York.

The medical examiner's office concluded the "Blue Bloods" star's death was caused by sustaining severe trauma and blood loss.

Williams is survived by wife Pamela Van Sant and two children, daughter Elinor and son Gill.

Treat Williams

Williams died June 12 following a vehicular accident. He was 71. (Emma McIntyre/Getty Images)

LIKE WHAT YOU’RE READING? CLICK HERE FOR MORE ENTERTAINMENT NEWS

"I have never experienced this kind of grief before, so it’s hard to put my thoughts into words, but I’ll try my best for now," Elinor said in a tribute shared a month after Williams' death. "I have been home with my family in Vermont for a month now, but it feels like just yesterday that I frantically got on a plane home after I got that phone call. It feels like he’s just away filming. However, I keep forgetting that he’s not coming home this time."

"This love is a once-in-a-lifetime love. A father's incomprehensible love for his daughter, and a daughter's boundless love and complete admiration for her father," she continued.

Treat Williams in a dark suit on the carpet

An autopsy revealed Williams died as a result of severe trauma and blood loss due to the crash. (Cindy Ord/Getty Images for Tribeca Film Festival)

CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER

Treat Williams as Lenny Ross on the set of "Blue Bloods"

Williams had over 120 acting credits to his name at the time of his death. (John Paul Filo/CBS via Getty Images)

"Dad, I love you more than words could ever describe. You have given me the best life imaginable, and I could not have ever dreamed of having a better father. Thank you for loving me completely. I know you will walk with me by my side for eternity."

Williams' nearly 50-year acting career included starring roles on the TV series "Everwood" and in the movie "Hair." He appeared in more than 120 TV and film roles, including the features "The Eagle Has Landed," "Prince of the City" and "Once Upon a Time in America."

CLICK HERE TO GET THE FOX NEWS APP

The Associated Press contributed to this report.