Motorcyclist Hit 164 MPH In St. Mary's County Crash That Killed 9-Year-Old Child, Sheriff Says

New details were released by investigators on Monday afternoon as they continue to probe the double fatal crash that left two dead.

Waldorf resident Tiernan Anthony Stevenson was killed in April after crashing into an SUV being driven by 36-year-old Hollywood native Stephanie Rose Robey, officials say.

The crash was reported shortly before 10:20 a.m. on Sunday, April 7. A 9-year-old passenger in the SUV was also airlifted with critical injuries and died at the Children National Medical Center in DC on Friday, April 19.

According to investigators, Stephenson was riding his motorcycle north on Three Notch Road when Robey pulled into his path while attempting to cross the road from Tom Hodges Drive.

Tiernan struck the rear driver's side door, was ejected from the motorcycle, and pronounced dead at the scene by first responders. Robey was rushed to MedStar Washington Hospital before being transported to DC.

The investigation, conducted by the Sheriff’s Office Reconstruction Unit, has determined the motorcycle's excessive speed caused the collision, officials said.

Footage from the helmet camera worn by Stephenson showed the motorcycle traveling 164 mph immediately before impact.

"The impact of this crash has left permanent scars on the families involved; it is devastating," St. Mary's County Sheriff Steve Hall said. "Witnesses and first responders are profoundly shaken by what they saw on April 7.

"It has been said many times before, but our message begs repeating: driving the speed limit and maintaining focus on the road must be intentional and habitual.

"The social contract between all drivers is one of the most important we make; it is rooted in the truth that every life—yours, your passengers, and those of others on the road—matters to someone.”

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