Blooper

At about the 25:54 mark when Grissom is looking at the pictures on the wall a man passes by the window, then about 5 seconds later, the same man, going in the same direction, passes by again.

Catherine tells a colleague that they knew the girl was a virgin because of her intact hymen. This is based on a common and outdated misconception, which is even "explained" in the episode by the victim having a c section. The status of a hymen is unrelated to any sexual activity, and the membrane often breaks as a result of physical activities like riding a bike or horse.

The baby was far too calm. A baby who had seen its mother cry, and then die, in a very loud way, then been left without food and without being changed all night and into the morning, would have been crying, a lot. Not calmly looking around and vaguely interested in the hammering on the door. The fact that the baby could see its mother would have made it worse. Babies (of the kind of loving parent Christina was) get cross when they feel ignored, so he'd have been crying as loud as possible to wake up the mother who appeared to be sleeping in front of him.