CHAPEL HILL, N.C. (AP) — Detectives investigating the slaying of the student body president at the University of North Carolina are trying to enhance two photos that show a possible suspect, officials said Monday.

The ATM machine surveillance photos show a young man in a baseball cap and hooded sweat shirt using Eve Carson's ATM card and driving a sport utility vehicle that may be her Toyota Highlander, authorities said.

Detectives also believe a dark shape in the photo may be a male passenger in the rear seat.

"We have been exploring ways to enhance the quality of this photo in an effort to learn more about this person," police said in a statement.

Police have not said when the photos were taken or given the location of the ATM machine, saying only that it is in Chapel Hill.

Carson, 22, of Athens, Ga., was found last week on a street about a mile from campus. She had been shot several times, once in the right temple.