New Delhi: The father of one of the accused in the brutal gangrape of a 23-year-old paramedical student from Dehradun in the heart of the national capital, on Tuesday said that if his son is guilty, he must be punished. Hari Ram Sharma, father of accused Vinay Sharma, said, 'We had no idea about the incident. If he is responsible for this, he should be given the toughest possible punishment. But if he is innocent, he should be let off.'