At the end of the episode, Mac and the first victim's father exit the apartment and turn right to leave the building. But at the beginning of the episode, that part of the hallway leads to the neighbor's apartment and nowhere else. If they'd wanted to actually leave the building they should have turned left.
In the closing scene, Gary Sinese's character picks up two boxes and starts exiting the victim's apartment. The bottom box is a cardboard file box with the end label and handle showing. In the hallway, Sinese is suddenly carrying the boxes using the handles on the file box.
When Danny has the librarian pull up the student ID, the computer screen shows she is a "SOPHMORE". The correct spelling is SOPHOMORE.