Delgado v. Trax Bar & Grill (2005) 36 Cal.4th 224 addressed when a business owner has a duty to undertake security measures (such as hiring guards) to protect patrons from third-party criminal acts. The court held that:

Explanation

Delgado v. Trax Bar & Grill (2005) 36 Cal.4th 224 held that the duty to take a high-burden precaution — like hiring security guards — generally requires heightened foreseeability of the specific kind of harm, typically demonstrated by prior similar incidents at or near the premises. Less burdensome precautions (lighting, locks, basic warnings) may be required on lower foreseeability. The case continues the Rowland framework but recognizes that the burden side of the equation matters. For guards already on duty under contract, the PPO owes a duty of reasonable care in performance of the security services it has undertaken.