ORLANDO, Fla. -

The criminal investigation sparked when University of Central Florida sorority pledge Ann Hefferin died nearly one year ago is still ongoing.

A federal agency is now working to perform tests on Hefferin's cellphone at the request of UCF police, spokesman Grant Heston said. He did not release any more details about the tests or why police were focusing on her phone.

The story gained attention when UCF police began investigating a fraternity that hosted a party Hefferin attended hours before her death. An autopsy later showed Hefferin died because of a bacterial infection, although she did have trace amounts of alcohol in her system.

It's not clear when the tests will be completed or when the criminal investigation will close. Once the criminal investigation is no longer active, UCF police records detailing the investigation become public. 

Major changes to UCF's alcohol policies pertaining to Greek organizations were enacted in the wake of Hefferin's death.