One of the people accused of being a supplier was a 30-year-old Brooklyn man, possibly better known to some as a seller of ice cream from a Mister Softee truck. Whatever money he saved, he said in an interview, he would eventually squander on cocaine to use or, occasionally, sell.

Another was a 23-year-old Polish immigrant said to have grown marijuana and manufactured hallucinogens in the East Village studio apartment where he lived with his girlfriend. She said in an interview that she tended to the two dozen or so plants and sometimes handled deals when he got too busy. The couple had planned to start a juice and health food business one day.

In the annals of notorious New York City drug cases, these suspects seem somewhat unremarkable, but for one thing: their Ivy League clients.

The three were swept up in an undercover investigation by the police that began in the summer and culminated last week in the highly publicized arrests of five Columbia University students who are accused of selling an array of drugs at several fraternity houses and other campus residences.