There is usually something distinctive about everyone. As soon as it is safe, write down everything you remember about the incident. Don't compare notes with other victims or witnesses. They could be wrong in what they think they saw. Self Protection You are ultimately responsible for your own protection.
Locks are only effective when they are used.
Rooms and offices left unlocked and unattended are an invitation to a thief. It's all a matter of common sense. You must always think ahead. Don't put yourself in a situation that common sense tells you is risky. Avoid high crime neighborhoods, especially at night.