The story

Timothy Krajcir got away with murder for decades, police say. They say he preyed on women he could easily overpower. He always struck at night to avoid detection. When he killed, he never spoke of it to anyone. Police even say they considered a cop might be behind the killings.

Authorities now say he may have honed his serial killing skills in the classroom, learning how police investigated crimes and figuring out ways to outsmart them.

Ironically, it was under a court-mandated order from a rape conviction that Krajcir got his degree at Southern Illinois University, Carbondale, where he graduated in December 1981 with a major in administrative justice, typically taken by those looking to enter law enforcement.

His undoing ultimately was something he could never have anticipated at the time -- DNA technology that would connect him to a murder and rape more than 25 years later.

Krajcir, who spent time for rape and other offenses over the years, apparently knew his killing spree eventually would catch up with him. Read full article »

CNN's David Mattingly contributed to this report.

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Serial Killer Caught
CNN's Anderson Cooper explores the unraveling mystery of Timothy Krajcir
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