In the last four weeks, there have been several cases reported. The thieves may be targeting people's tax documents.
Police said some residents discovered the thefts when they tried to file their returns but were told someone else had already done it.
Identity thefts have been confirmed at several addresses off Valley Vista Boulevard in Sherman Oaks.
Investigators advised people to watch out for anyone hanging around mailboxes. They also said it's a good idea to get to know your mail carrier.
