After determining that a man they had detained was not the killer, Rhode Island officials have searched for more evidence and released photos of a possible gunman.

© Christopher Capozziello for The New York Times

The authorities released more video footage in an attempt to identify a suspect, and said they had no idea why the killer attacked a study session.

A person of interest was in custody Sunday, the day after two people were killed and nine others injured during an attack on the Rhode Island campus.

© Mark Stockwell/Associated Press