Burglar picked our lock while we were inside

[Dog Woman]

Soundly sleeping in one Saturday and someone, in full daylight of 8:00 am, picked our lock. Our deadbolt was locked. I thought it was my hubby who typically gets up earlier than me and I called out "Good morning" and then I heard the door close quietly. Did not discover he wasn't up early until I was wide awake and he was still in bed. Could not believe it. Then I got scared that someone had actually broken into our rig while we were in bed! Good thing this person was not a serial killer or something like that! Has anyone else had this happen to them? We thought someone must have had a master key, but discovered scratches and evidence someone had jimmed the lock. Hubby and I have talked & talked about this subject, but he says there is no way to protect yourself from someone so bold that would pick a lock in broad daylight. I suggested adding a sliding-chain type lock you see people add on apartment entry doors. What would you do?