Radel's death spurred Gilbertson to dig deeper into the drownings. He and two graduate students scoured the Internet, newspaper stories and police reports. They found 22 victims who went to college within 50 miles of I-94 between Moorhead, Minn., and East Lansing, Mich.
The victims were white or Asian men in their early 20s, generally around 5-foot-8 and 165 pounds and athletic, with good grades. No victims were women.
They also found that 15 of the cities where the drownings took place were within 100 miles of I-94. Eighteen of the 22 drownings occurred during the first two weeks of the month, and three-quarters of the disappearance occurred when the moon was less than half-full.
Gilbertson said he can't judge some cases because he doesn't have enough information. He also acknowledges some are accidental. But others could be murders.