"This is our biggest break so far in this case," Curran said.
Eve Carson, 22, of Athens, Ga., was found Wednesday morning lying on a street about a mile from campus. She had been shot several times, including once in the right temple. Her sport utility vehicle was discovered Thursday, a few hours after police positively identified her as the victim.
She appears to be the victim of a random crime, Curran said.
Curran said police have circulated the picture with police departments in North Carolina, hoping their officers can help identify the suspect. The ATM photos show a young man in a baseball cap and hooded sweat shirt driving a sport utility vehicle that may be Carson's Toyota Highlander, Curran said. There does not appear to be anyone else in the SUV.
Carson was last seen around 1:30 a.m. Wednesday, when she stayed behind at home to study while her roommates went out for the night. She was known to work late at her campus office, and Curran has said Saturday that "she may have mentioned something about needing to print off papers later that night."
But Curran has said police don't have any evidence that she made it to her office. There were no signs of forced entry to her home and police said they are not aware of anyone who might have been angry with Carson. There are no indications she had been sexually assaulted.
Along with the photos, authorities remain focused on Carson's truck, found illegally parked a few blocks from her home. They have said the killer had access to her vehicle, but have declined to provide other details. They again asked Saturday for the public's help, asking anyone who might have seen it between early Wednesday morning and Thursday afternoon to come forward.
Curran said investigators also have Carson's cell phone records and are using them to help construct a timeline of her final hours.
Police found Carson's body shortly after 5 a.m. Wednesday, after two callers to 911 reported hearing several gun shots. One of the callers also heard a woman scream as the shots were fired.
Carson's death struck hard at North Carolina, where she was prestigious Morehead-Cain Scholar and leader who invited all incoming students to stop by her office for a chat. Her death led to a pair of memorial services on Thursday, attended by thousands, and a third is likely after classes resume following next week's spring break.
University Chancellor James Moeser plans to lead a delegation of senior administrators to services this weekend for Carson at her home in Athens. The school's Board of Trustees, of which Carson as a member, has offered a $25,000 reward for information leading to an arrest in her death.