37-year-old Peter Visconti Jr. made his first court appearance and bail was set at $25,000.
Visconti, who is accused of driving while ability impaired by drugs, was apparently on Xanax, prosecutors said.
Police say he was driving a truck in Shirley when he struck a minivan, then crossed the median into oncoming traffic and hit a motorcycle and another minivan.
One woman, a tourist from China, was killed and several other people were hurt.
"This is a real tragedy," said Suffolk County District Attorney Timothy Sini. "You have individuals who are seriously injured, we have one loss of life and it just shows how vigilant we have to be."
Visconti was also charged with unlicensed operation of a motor vehicle and criminal possession of a controlled substance.
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