Ironically, his friends at the University of Notre Dame called him "Smiling Chad." That's what one of the residents of Fisher Hall told the Tribune in early 2003, after Chad Sharon, a student from Wisconsin, was found in the St. Joseph River near Angela Boulevard.

He had been missing since December 12, 2002, when Sharon attended a house party in the 500 block of Corby Boulevard and never returned.

Sharon's tragic death was ruled an accident, and there's never been any public evidence to the contrary.

But now, his name has come up again as a pair of investigators look at possible links in up to 40 drowning deaths across the nation, links they say may point to a serial killer at work.

Sharon, a white, college-age male who was out drinking, disappeared and then was found drowned, fits the profile of cases that two retired detectives from New York say may be related — and may not be accidental at all.

And in South Bend, there are people asking if perhaps there's a link. There's already a posting questioning Sharon's death at SouthBendForum.com.

It's all because of the publicity surrounding the "Smiley Face" cases, investigated by criminal justice students at St. Cloud State University in Minnesota and the detectives, Kevin Gannon and Anthony Duarte, whose interest began with just one case years ago.

In South Bend, police never found a connection at the time of Sharon's death, despite some questions because there were five college-age people who'd gone missing between October and December 2002, all between here and Minnesota.

At the time, a Notre Dame spokesman told the Tribune that the FBI and the agencies involved in all the cases had been notified and worked with Notre Dame Security Police, but no link was discovered.

There's still no hard evidence that there is one.

Dennis Brown, the current spokesman for ND, said Wednesday that he'd heard the media reports, but the university had no comment until they further investigated the degree to which Duarte and Gannon had contacted officials at the school.

But at St. Cloud, criminal justice professor Lee Gilbertson encouraged his students to take a closer look at the drowning death patterns.

During their investigative work, the Chad Sharon case was one of more than a dozen they looked at, according to two of those students who told Chicago news anchor Mark Suppelsa about their research in May 2006.

Now, Gilbertson and at least one St. Cloud criminal justice graduate student, Adam Carlson, have been working with Gannon and Duarte to establish any pattern among 40 deaths like Sharon's. Information about the detectives and the team can be found on the Web at http://nationwideinvestigations.us/theteam.html

Duarte and Gannon have told national media outlets there is a link, based on graffiti found at the scenes of suspect drownings in several Midwestern states including Indiana.

In many cases a "smiley face" signature was noted. But in at least one Michigan case — reported by numerous media outlets in the Midwest, as well as national network MSNBC and WTMJ in Milwaukee — the strange word "sinsiniwa" left at the scene near a Lansing drowning death was a mystery.

Until, Duarte and Gannon told reporters, they realized it was a location name for another drowning death they were investigating in East Dubuque, Iowa.

Both the St. Cloud researchers and the detectives have met with skeptics. But in at least one case, that of Christopher Jenkins in Minneapolis, the case was changed from an accidental drowning to a homicide after further investigation, KSTP-TV reports there.

Jenkins was 21 years old when he went missing on Halloween night in 2002. And he was still missing two weeks after Sharon disappeared in December, because the Jenkins case was one of the other four that was checked for any connection when Sharon went missing.

The work of Duarte, Gannon and the investigative team has law enforcement agencies taking a second look across the country.

In Cleveland, WKYC reports the possible involvement of an Ohio University student. At KSTP, where the story first broke, authorities in Cincinnati told reporters they're changing how they investigate drownings to check for patterns.

And in St. Cloud, where Gilbertson first took a look at drowning death patterns along the lakes and rivers, authorities told reporters they want to re-examine their cases, too.