What program is this episode from? i think it may be law and order svu, law and order or csi?

I want to find out what program this episode is from, well it goes something like this....... Two young girls (approx 17), have been out for the night drinking. They happen to look very alike and are best friends. So because one is too drunk she gives her license to the other girl to drive home with. However they get into a tragic car accident, and one girl dies and the other is in a coma. But the investigating team mistakenly mix up the girls identity's as the dead girl had the other girls licence in her pocket. The mother of one of the girls gets really mad and distraught and suffocates the girl that is just waking out of the coma. Thinking it is her daughters friend, she does this because she blames her daughters best friend for leading her daughter astray and being a bad influence. In the end the mother finds out about the mistaken identity mix up and realises she in fact murdered her own daughter. Its a good episode and i want to know what program it was and possibly what season or episode number. If anyone could help i would really appreciate it. Thanks guys!