Murder Most Ghostly Ghost

Charlie and Lizzie are ghosts. As ghosts they can go anywhere they want and listen in to conversations without anyone knowing they are there. Using this, they have decided to become ghost detectives. Previously, they managed to solve the case of who murdered Charlie. Now they have a new case to solve when a murder happens right in front of them. As ghosts, their problem is how do they let the police know what they have found out. The only way they can affect alive people is by raising or lowering the temperature and blowing cold wind. Can they solve their new case and guide the police to the murderer? Charlie has some ideas for how he can do it.