One of the missing University of South Florida doctoral students was found dead and his roommate has been arrested, local authorities said Friday.

Zamil Limon’s remains were found on the Howard Franklin Bridge in Tampa, Chief Deputy Joseph Maurer with the Hillsborough County Sheriff’s Office said. Investigators are still searching for Nahida Bristy, he said. 

Limon and Bristy, both 27, were last seen in the Tampa area on April 16.

Deputies with the sheriff’s office took 26-year-old Hisham Abugarbieh, a roommate of Limon, into custody on Friday. He faces charges of domestic violence and evidence tampering, as well as a charge of failing to report a death to law enforcement.

Abugarbieh, a U.S.-born citizen, had been barricaded at a home in the Lake Forest Community, a neighborhood near USF’s Tampa campus, the sheriff’s office said earlier Friday. The entrance and exit of the Lake Forest Community was briefly shut down due to the law enforcement activity.

The sheriff’s office had elevated Limon and Bristy’s status to endangered on Thursday.

“Recently, information that has come to light has led detectives to consider the two endangered,” the HCSO said in a statement. It did not give details about the information.

Limon was studying the use of AI in environmental science and was set to present his doctoral thesis this week, his family said. Bristy is studying chemical engineering. 

Bristy’s older brother, Zahid Pranto, told CBS News that Bristy would typically be in touch with her family on a daily basis.

“There has been no single day without contact with her,” Pranto said. “My family is just devastated.”