The 15-year-old was riding his Kawasaki dirtbike on Sept. 24, 1992, when he struck an electrical cable strung between two trees, troopers say.
According to a contemporaneous report from the Allentown Morning Call, the wire slashed his windpipe and he fell, fracturing his skull. A backseat passenger was also thrown from the bike but not seriously injured.
It happened on a trail along railroad tracks parallel to the Lehigh River in North Whitehall, state police say.
Then-District Attorney Robert Steinberg called the incident "an intentionally malicious and wicked act," and his death was ruled a homicide by the Lehigh County Coroner's Office, per the newspaper report.
Still, no suspect or apparent motive has since emerged.
At the time of his death, Keller was a sophomore at Northampton High School, a football player, and a Morning Call paper carrier, according to the outlet.
Anyone with information is asked to call PSP Troop M at 610-861-2026 or PSP Tips at 1-800-472-8477.
Click here to read the Morning Call's 1992 coverage.
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