why did the intruder enter gerrards cottage

The Intruder entered Gerrard's cottage because he wanted to kill him and take his identity because he was Gerrard's look alike. He wanted to escape from the cops as he was a jewel robber and a murderer on run.

Gerrard live alone in A lonly cortage. The intruder, who was a criminal enter his cortage with an intention of murdering him. The intruder considered Gerrard to be a mystery men, who hardly interested with anyone. The intruder wanted to take his identity and be called Gerrard so, that he could live peaceful at his cortage for a while as the police was looking for the intruder

 The intruder was a criminal. He had also killed a policeman. He was, now, being chased by police. He thought that he ressembled Gerrad in body. He decided to kill Gerrad and then live himself as Gerrad. So he broke into the cottage of Gerrad.