Anyway, to the best of my memory the books are about a vampire boy who goes to a human school at night(with other beings of the night like wolves, zombies, other vampires, etc.) because its time for them to go to school since the humans were to have left school for the night. This vampire boy meets a girl and her brother, who i believe is younger than she is, and he befriends them bith and they find out he is a vampire. At one point he takes them to his house to meet his family but since they are human he gives them some jackets that make them smell like zombies instead of humans so they wont get caught.
In the last book the vampire boy ends up killing the girl's younger brother.
Now that is all i can remember from the book with the exception that one of tge books had the images of a boy carrying a girl on his back as he climbed the wall.
It may also be helpful that these characters were closer to pre-teen ages. Thanks in advance for the help.