Theft in beauty salon

[Seb04]

How to prevent the burglary from the beauty salon? My younger sister is running a beauty salon named Daffodils in Toronto. It is a beauty salon that has good daily income. But recently, she had been facing burglary issues. Few of her the cosmetic products were found missing. All those ere really expensive. At present she bought new cosmetic products instead of the lost one. But she doesn't want this situation to happen again. She really needs to know who is behind this burglary. Is it the workers or the customers. I suggested to install security cameraS in her shop to identify the thief. Is it necessary to install security sensors in the shop?