SEATTLE -

The King County prosecutor has filed a vehicular homicide charge against a man accused of causing a fatal, fiery crash as he drove along Interstate 405 in suburban Bellevue at speeds exceeding 120 mph.

Samuel Sampson of Woodinville was also charged Thursday with vehicular assault and reckless driving.

Prosecutors allege the 27-year-old man was weaving through traffic at excessive speeds on the night of Sept. 12 when his car slammed into the rear of a car being driven about 60-70 mph by 22-year-old Ian Beckford of Federal Way. Beckford's car spun out of control, eventually bursting into flames. He was killed.

In court documents, prosecutors say Sampson told officers he had injected methamphetamine and had used heroin earlier that evening because he was bored.

Held on $1 million bail, Sampson is scheduled for arraignment Sept. 30. He was represented by a public defender at an initial court hearing.