How does my son recover his personal belongings in her ex-girlfriend's home?

He should write them that under California law he is entitled to recover his personal property and if he is not given a reasonable opportunity to do so, they are liable to civil suit for conversation of property which allows him to recover the fair market value, interest at 7% from the date he was prevented from taking his property, and the costs of suit. ?he might also be entitled to attorney fees [the Code Section governing conversation suggests that is an additional remedy but a judge I tried a similar case in front of did not allow it].