1) It's Voldemort Not " Vaultimort" LOL
2) The spell was the killing curse : Avada Kedavra
Voldemort did not enter the Potter's home specifically to kill Lily and James. He was there to kill only Harry, not Lily, due to the piece of the prophecy Snape had conveyed to him. However, Voldemort really did not care who he left dead in his wake. James tried to get in his way to give Lily and Harry a chance of escape, so he was killed without a second thought. Lily stood between Voldemort and the infant Harry. Due to the fact that Snape had requested mercy on Lily's behalf, Voldemort gave her the choice of moving out of his way. When she refused him, he killed her anyway.
