After a University of South Florida doctoral student was found dead on a Tampa Bay bridge, his roommate has been charged with killing him and his friend – also a USF doctoral student – the sheriff’s office said Saturday.

Hisham Abugharbieh has been charged with two counts of first-degree premeditated murder with a weapon in the deaths of the 27-year-old Bangladeshi students, Zamil Limon and Nahida Bristy. The two had been missing since last week.

“Evidence was presented to the State Attorney’s Office, resulting in further charges against Abugharbieh. At this time, the search for Bristy continues,” the Hillsborough County Sheriff’s Office said.

Limon’s body was found on the Howard Frankland Bridge in Tampa on Friday, while Bristy has still not been found, the sheriff’s office said.

However, investigators called Bristy’s family in Bangladesh saying they believed she may be dead, based on the amount of blood found in Limon and the suspect’s shared apartment, Bristy’s brother told CNN affiliate WTSP. CNN has reached out to her brother and the sheriff’s office for details.

Hillsborough County Sheriff’s Office Marine and Dive teams were seen searching the water near the Howard Frankland Bridge for Bristy on Friday.

A medical examiner is still determining Limon’s cause of death and may share autopsy results over the weekend, Chief Deputy Joseph Maurer with the Hillsborough County Sheriff’s Office said.

“This is a deeply disturbing case that has shaken our community and impacted many who were hoping for a safe resolution,” Sheriff Chad Chronister said in a statement on Friday.

Abugharbieh was arrested Friday morning after law enforcement was called to his home for a reported domestic violence incident, according to Maurer.

In addition to the murder charges, Abugharbieh, a 26-year-old former USF student, is facing charges of unlawfully moving a dead body, failure to report a death with intent to conceal, tampering with physical evidence, false imprisonment and battery, the sheriff’s office had said.

Abugharbieh made an initial court appearance Saturday morning and will be held in jail until a pretrial detention hearing on April 28, according to Hillsborough County State Attorney’s Office spokesperson Erin Maloney. At the pretrial detention hearing, “prosecutors will argue that he remains a danger to the community and should remain behind bars until trial,” Maloney said.

The initial charges are based on probable cause. Official charges will follow after the Hillsborough County State Attorney’s office reviews the evidence in Abugharbieh’s case, Maloney said.

It’s unclear whether Abugharbieh has an attorney. CNN has contacted the Hillsborough County Public Defender’s Office to see if it will represent him.

Limon and Bristy were reported missing by a family friend on April 17. They were last seen around the university campus the previous day, according to the university’s police.

Limon’s family told CNN they had become desperate for answers about what happened to the joyful, promising young researcher.

As the investigation and search for Bristy continues, Moez Limayem, the university’s president, said his staff will remain in contact with the students’ loved ones to provide support.

“Please join me in praying for the families and friends of Zamil, and for the safe return of Nahida,” Limayem said in a message to faculty and students.

Roommate had been on investigators’ radar

Before his arrest Friday, Abugharbieh had been interviewed at least twice by law enforcement. He was initially talking to authorities but stopped cooperating as he was being questioned again Thursday, Maurer said.

By Friday, the chief deputy said investigators were able to “link the suspect to this case and to (Limon’s) body.”

During his arrest, Abugharbieh barricaded himself inside a home, requiring a SWAT team and crisis negotiators to respond, the sheriff’s office said. Video of his arrest shows an armored vehicle parked in the front yard as Abugharbieh walks out the front door with his hands up and a bath towel tied around his waist.

Abugharbieh was arrested at his family’s home, where a judge had previously prohibited him from entering due to domestic violence allegations made by his brother.

The suspect was arrested twice in 2023 on charges of battery, which were later dropped, according to court records. But after one of those incidents, his brother filed for an injunction that prohibited Abugharbieh from coming near him or his home. In court filings, the brother alleged Abugharbieh attacked him and his mother during an argument in which the brother was telling him to get out of the house.

When the injunction expired last May, the brother asked the court to extend it, saying he didn’t want to “run the risk of him returning.” His request was denied.

The suspect had attended USF between 2021 and 2023 while he pursued a bachelor’s degree in management, a spokesperson for the university told CNN.

‘We are becoming numb,’ student’s brother says

The students had been missing since last week, prompting friends in Florida and relatives in Bangladesh to look for answers.

Before Limon’s body was found, his brother told CNN the family was in “deep pain” awaiting news.

“It’s devastating for us,” Zubaer Ahmed said. The brother said his family has been anxiously following updates. “We are becoming numb. Anything could be possible. We just want to know the truth or what happened to them. It’s not possible that two students disappear out of nowhere.”

Limon was last seen on April 16 around 9 a.m. at his off-campus home, about three blocks from the university’s campus, police said. He had been pursuing a degree in geography, environmental science and policy since the fall of 2024.

Bristy was last seen about an hour later at the Natural and Environmental Sciences Building on campus, police said. She enrolled at the university last fall and was studying chemical engineering.

The following day, a family friend was unable to reach the pair and notified campus police.

Detectives had been following leads and conducting searches in multiple locations when the Hillsborough County Sheriff’s Office elevated the pair’s status to “endangered” on Thursday, citing new “information that has come to light.”

Limon had discussed marrying Bristy

Limon had spoken highly of Bristy to his family in Bangladesh, telling them he was courting her and the pair had discussed the possibility of marriage, his brother said.

“He shared that she is a good girl, and she has a lot of talent, like she can sing and cook well,” Ahmed, the brother, said.

Limon had been hard at work on his thesis for the past two years, studying how to use generative AI to monitor shrinking wetland in South Florida, his brother said.

“My brother is very decent and a very simple person,” Ahmed said. “He always put a smile on his face.”

After completing his PhD, Limon wanted to return to Bangladesh and get a job as a university professor, Ahmed said. (CNN)

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