Sousa was seen talking to a man in a car around 2 a.m. Wednesday when he grabbed her purse and sped away. Sousa became entangled in the handbag and was dragged about 20 feet before she came loose and hit the asphalt, Carbajal said Thursday.
He said police were investigating the crime as a homicide and working to find the car's driver. Other people were seen in the car, and police hoped they come forward, Carbajal said.
"Somebody knows something, and we need that person to come forward," he said. "We need that one call, that one piece of information to lead us to a suspect or suspects in this case."
Karen Montenegro, Sousa's mother, wept as she spoke to reporters Thursday about her daughter's death and sent a message to those in the car that dragged her.
"Please just turn yourself in and do right by me," she said.
Sousa is listed on ASU's directory as a communications major.
Friends held a memorial for her Thursday night in Bay Head, N.J.