## Facts

- Marianne Saelzler, a Federal Express delivery employee, entered a large apartment complex owned by Advanced Group 400 to deliver a package in the afternoon.
- She was attacked by three unidentified assailants who beat her and attempted to rape her; the assailants were never identified or apprehended.
- The complex had a history of serious criminal activity, including gang presence and prior assaults and sexual assaults or attempted sexual assaults.
- Saelzler alleged the complex’s perimeter gate(s) were frequently left open and that, on the day of the incident, a gate was ajar.
- The owners had some security measures in place, including periodic gate inspection/repair and nighttime (but not daytime) security patrols.
- Saelzler’s security expert opined that additional security measures (e.g., improved gate maintenance and additional guards) would have prevented the attack.
- Saelzler sued the owners for negligence, alleging they failed to provide reasonable security and warnings despite knowledge of criminal activity.

## Issues

1. Whether the plaintiff produced sufficient, non-speculative evidence that the owners’ allegedly inadequate security was a substantial factor in causing the criminal attack, sufficient to defeat summary judgment.

## Decision

- The California Supreme Court reversed the Court of Appeal and reinstated summary judgment for the defendants.
- The Court assumed arguendo that a duty of reasonable security could exist and that security measures might have been inadequate, but held causation was not shown.
- Because the assailants were unknown and there was no evidence whether they were trespassers or lawful entrants, the claim that better security would have prevented the attack rested on speculation.
- Generalized expert testimony asserting that additional security would have prevented the attack did not supply the missing causal link.

## Legal Principles

- In negligent-security premises liability, even if duty and breach are arguable, the plaintiff must present evidence that the security deficiency was a substantial factor in causing the injury.
- Causation requires proof that it is more probable than not that additional or different security would have prevented the harm or made it significantly less likely; possibility and conjecture are insufficient.
- On summary judgment, a defendant may prevail by showing an absence of evidence on an essential element such as causation; the burden then shifts to the plaintiff to raise a triable issue with non-speculative proof.
- Expert opinion cannot establish causation where it assumes unproven facts (such as how unknown assailants gained access) rather than grounding the opinion in evidence tied to the incident.

## Conclusion

The court held that, without evidence identifying the attackers or showing how they entered and whether enhanced security would likely have stopped them, the plaintiff could not prove causation; summary judgment for the property owners was proper.


Saelzler v. Advanced Grp. 400, 25 Cal. 4th 763, 23 P.3d 1143 (Cal. 2001)