Dhaka, April 29 -- The families of two Bangladeshi students murdered at the University of South Florida (USF) are demanding justice as chilling details emerge about the suspect Hisham Abugharbieh, who was described by victims' relatives and even his own brother as a "violent psychopath".

Zamil Ahmed Limon and Nahida Sultana Bristy, both PhD students at USF, had been missing since Apr 16.

On Friday, police recovered Limon's body stuffed inside a black bag near the Howard Frankland Bridge.

While Bristy remains missing, police informed her family that she was also killed.

On Monday, human remains were found in a local pond, though the medical examiner has yet to confirm if they belong to her.

Limon's younger brother Zubaer Ahmed told lo...