EAST ST. LOUIS (AP) — A British man faces at least 20 years in federal prison after being convicted of charges that heroin he sold to dozens of students at a southwestern Illinois high school student killed one of them.

Jurors in East St. Louis found 41-year-old Richard Klemis guilty Wednesday of heroin-related charges.

Prosecutors say Klemis was a British citizen living with his mother in O’Fallon, in 2010 and 2011 when he sold heroin to dozens of current and former O’Fallon Township High School students. They included 19-year-old Tyler McKinney, who died of an overdose in February 2011.

Klemis fled to Great Britain but was captured and eventually returned to the U.S.

Sentencing is scheduled for May 8.