If the test determines he is 18 years or older he will be treated as a legal adult, said the officer, who spoke on condition of anonymity because he was not authorized to disclose sensitive information.
The brutality of this case has made Indians confront the reality that sexual violence is deeply entrenched in the society.
Women face daily harassment, from catcalls on streets and groping in buses to rapes.
Often police refuse to accept complaints by victims and even blame them for inviting unwanted male attention by dressing provocatively.
Families too dissuade victims from coming forward in the belief that it will ruin their reputations.
Activists hope that the savage assault on the young woman, a physiotherapy student, will shake off the taboo associated with sexual violence and make the authorities take such cases more seriously.
