Nahida S. Bristy (left); and Zamil Limon.Credit : University of South Florida Police Department; Facebook

The families of University of South Florida doctoral students Nahida Sultana Bristy and Zamil Ahamed Limon have released a joint statement days after an arrest was made in connection with their disappearances.

Bristy and Limon, both 27, were reported missing from Tampa, Fla. on April 17.

Limon’s body was later found on Howard Frankland Bridge on Friday, April 24. His 26-year-old roommate, Hisham Abugharbieh, has been charged with two counts of murder in connection with the case.

On Sunday, April 26, the families of Bristy and Limon issued a joint-statement with requests and questions for authorities.

In a six-point memo, the families called on the University of South Florida to investigate Avalon Heights, the housing facility where investigators said Limon and Abugharbieh lived.

“We believe it is important to investigate why a roommate was assigned without proper background checks or without informing the residents of any relevant concerns,” read part of the statement.

It further demanded to know why Avalon Heights does not have proper security cameras on the property or why the “security system was not strong enough to protect its residents.”

“Even after complaints were made, why was no strong action taken?” the statement read, in part. Limon’s brother recently told WFLA that he had made complaints to Avalon Heights about Abugharbieh’s alleged behavior.

PEOPLE has reached out to Avalon Heights for comment but has not yet heard back.

The university tells PEOPLE while the school doesn’t own the apartments, they “recognize the importance of the safety and well-being of our students wherever they live” and are cooperating with law enforcement.

“We are actively working with law enforcement and relevant authorities as they investigate this tragedy, and we fully support efforts to examine all factors involved, including housing conditions and safety measures that are in place,” the statement read.

The listing for Avalon Heights on the university’s off-campus housing has been taken down from the website.

Both Bristy and Limon’s families were financially reliant on them, the joint- statement further said, requesting that their bank balances, assets and salaries be forwarded to the families.

The families are requesting that Bristy and Limon’s personal belongings, including their accessories, documents, laptops and clothings be returned to them in their native Bangladesh “exactly as they were found, without being altered, hidden, or tampered with.”

They have further called for the University of South Florida to establish a memorial to honor the memories of Bristy and Limon and “to help prevent such tragedies in the future.”

Bristy has not been located.

Authorities said in a criminal affidavit obtained by PEOPLE that they have not recovered any evidence to indicate Bristy is still alive and that they found a large amount of blood in Abugharbieh’s residence that matches Bristy’s DNA.

On Sunday, April 26, the Hillsborough County Sheriff’s Office said they found additional human remains at the same location where they’d found Limon’s body, and those remains have been sent to Pinellas County coroner for identification.