No arrests had been made or suspects identified in the case as of Tuesday, according to police, and there is a $20,000 reward for arrest and conviction in relation to the killing.
Children's Hospital of Philadelphia released a statement Tuesday afternoon saying Ketunuti was a second-year infectious diseases fellow and researcher. She had been at the hospital for five years, the statement said, and had also served as a resident in the Department of Pediatrics.
"Melissa was a warm, caring, earnest, bright young woman with her whole future ahead of her," Dr. Paul Offit, chief of the hospital's division of infectious diseases, said in an e-mail statement.
"But more than that, she was admired, respected and loved by those with whom she worked here ... Her death will have a profound impact on those who worked with her and we will all miss her deeply."