The Reno Police Department announced Tuesday morning that the Federal Bureau of Investigation has officially joined the investigation into the disappearance of 19-year-old Brianna Denison. The FBI has opened its own criminal investigation and has assigned an agent to work with the Reno Police Department.

Denison went missing from her friend's home near the University of Nevada around 4 a.m. Sunday morning.  Police say friends last saw her asleep on the couch in front of an unlocked sliding glass door.  Police found drops of blood on a pillow she was using, and they say the teddy bear her friend gave her to add support to the thin pillow is missing.

Denison is a Reno High School graduate and a psychology student at Santa Barbara City College in Santa Barbara, CA.

Police say Denison has not contacted her mother or brother who live in Reno, any of her friends, or her boyfriend who lives in Oregon.  

Investigators also say Denison may have been barefoot when she disappeared. She left behind her purse, cell phone, and her only clothing items, which were two pairs of shoes and a skirt outfit.

She is described a 5-feet tall, 98 pounds, with long brown hair and blue eyes.  Police are asking anyone with information to call a 24 hour tip line at 745-3521 or Secret Witness at 322-4900.