March 30, 2013 -- New surveillance video footage of a missing Brown University student on the morning of his disappearance may provide authorities with new clues to help locate him.
New images from a surveillance camera show 22-year-old Sunil Tripathi, of Radnor, Pa., moments after leaving his apartment at 1:33 a.m. on March 16, just 20 minutes after he last used his computer. Police said he left his wallet and phone behind.
"Typically, two reasons people don't take the normal things they take with them is because they're stepping outside to talk to somebody, they're going half a block away, or they're not coming back," ABC News consultant and former FBI agent Brad Garrett told "Good Morning America."
"His state of mind in those last interactions on the computer, in the last few hours that people knew where he was is important to assess," Garrett said.
Authorities searched Tripathi's computer and bank accounts, but reportedly found nothing. They also found what they have called a vague note in the student's apartment, but will not reveal the contents of the letter.
Police are hoping the video surveillance images of the missing philosophy major may provide new leads in the investigation.
Two weeks have passed since Tripathi was last seen by his housemate.
The FBI has joined the Providence Police Department and the Brown University Department of Public Safety in the investigation, which has expanded to Boston, Connecticut, New York, and Philadelphia, according to a statement from the school.
Meanwhile, Tripathi's brother and sister, Ravi Tripathi and Sangeeta Tripathi, have been casing the Providence, R.I. area in hopes of uncovering new leads in the search for their missing younger brother.
"We've just been literally walking every road we saw him walk. Walking in every nook and cranny, talking to every local business, and really trying to move forward," Sangeeta Tripathi said.
"Everyone's racking their brains to see if they can come up with places that he might be or where he might have gone," Ravi Tripathi said.
Tripathi's brother described Sunil as quiet, saying "he found really simple things made him very happy."
"He was a musician and listened to classical music," he said.
Sunil Tripathi was last seen wearing a pair of blue jeans, a black Eastern Mountain Sports ski jacket, glasses and a Philadelphia Eagles wool hat. He is 6-feet tall and weighs 130 pounds.
A Facebook page was created to aid in the search for the missing Ivy League student.
"Surveillance and imaging provide new clues to the continued search, and equally important, a boost of energy for all of us in the coming days," read a post on the page. "We love you, Sunny, and we hope to see you soon."