Written and reviewed by Josh Kohanim, Esq., California Bar No. 328609 · Published · Reviewed
In this guide
This page was checked against the statutes, the 2026 edition of California's civil jury instructions and the cases it cites on November 11, 2026. Our negligent security page explains who these claims can be brought against, and our premises liability page covers injuries caused by the condition of a property.
Elements of the claim
CACI No. 1000, the premises liability jury instruction, requires proof in a negligent security case that the defendant owned, leased, occupied or controlled the property and "was negligent in the use or maintenance of the property." The injured person must also show harm, and that the negligence "was a substantial factor in causing" it. CACI No. 1005 adds the duty that applies to crime. In practice the case turns on three questions: whether the attack was foreseeable, whether the owner's safety steps were reasonable, and whether a reasonable step would more likely than not have prevented the attack or the injury.
Duty and breach
California's jury instruction on crime on property, CACI No. 1005 (2026 edition), says that a landlord or the owner of a business open to the public "must use reasonable care to protect" tenants, guests or patrons "from another person's criminal conduct on" the property "if the [owner/landlord] can reasonably anticipate that conduct." Whether that duty exists is decided by the judge; whether the steps the owner took were "adequate and reasonable under the circumstances" is decided by the jury.
The judge's ruling on duty can end a negligent security case before trial. "Foreseeability, when analyzed to determine the existence or scope of a duty, is a question of law to be decided by the court" (Ann M. v. Pacific Plaza Shopping Center (1993) 6 Cal.4th 666). Several cases on this page ended on summary judgment, a ruling made from written evidence without a trial, so proof of warning signs is gathered early.
Prior similar incidents
Prior similar incidents are earlier crimes on the same property of the same general kind as the attack. They are the usual proof that an attack was foreseeable. In Ann M. (1993), the California Supreme Court held that the foreseeability needed to require security guards "rarely, if ever, can be proven in the absence of prior similar incidents of violent crime on the landowner's premises." In Castaneda v. Olsher (2007) 41 Cal.4th 1205, the Court said a plaintiff seeking guards must show "prior similar incidents on the premises or other sufficiently serious 'indications of a reasonably foreseeable risk of violent criminal assaults.'" Prior incidents are the main proof of foreseeability, but not the only one. Our page of California negligent security cases states each holding in one paragraph.
Nearby crime and general trouble
Crime nearby and general disorder are weaker proof of foreseeability than violence on the property itself. Castaneda v. Olsher (2007), citing Ann M., said crimes at an immediately neighboring, substantially similar business "can help to show the requisite foreseeability." In Sharon P. v. Arman, Ltd. (1999) 21 Cal.4th 1181, the Court refused to treat underground parking garages as "so inherently dangerous" that guards were required without prior similar incidents. A Court of Appeal held that knowing of "a general potential for rowdy or troublesome conduct by bar patrons" did not make "aggressive parking lot assaults reasonably foreseeable" (Williams v. Fremont Corners, Inc. (2019) 37 Cal.App.5th 654, as quoted in CACI No. 1005).
The sliding scale
California courts weigh how foreseeable a crime was against how burdensome the missing safety measure would have been. Castaneda v. Olsher (2007) adopted this method from Vasquez v. Residential Investments, Inc. (2004) 118 Cal.App.4th 269: "The more certain the likelihood of harm, the higher the burden a court will impose on a landlord to prevent it; the less foreseeable the harm, the lower the burden a court will place on a landlord." Castaneda calls it a "sliding-scale balancing formula," quoting Delgado v. Trax Bar & Grill (2005) 36 Cal.4th 224. A cheap repair needs little warning, and hiring guards needs a great deal. The table below shows where the published cases place four common measures.
| Security measure | Burden, as the courts describe it | Foreseeability required | Case |
|---|---|---|---|
| Hiring or posting security guards | Rarely, if ever, a "minimal burden" | Heightened: usually prior similar violent crimes on the property | Ann M. v. Pacific Plaza Shopping Center (1993); Delgado v. Trax Bar & Grill (2005) |
| Acting to remove a dangerous tenant, up to eviction | Eviction "cannot be considered a minimal burden" | Violence by that tenant or the tenant's guests that is highly foreseeable | Castaneda v. Olsher (2007); Madhani v. Cooper (2003) |
| Responding to an attack unfolding in front of staff, such as calling 911 | A 911 call is "generally minimally burdensome" | Actual notice of an impending or ongoing assault | Delgado v. Trax Bar & Grill (2005); Morris v. De La Torre (2005) |
| Repairing a known gap in an apartment's front door | About $15 for a missing glass pane | "[A] slight likelihood that an intruder might seek to enter" | Vasquez v. Residential Investments, Inc. (2004) |
The owner's knowledge
What the owner actually knew is the center of the proof of foreseeability. A Court of Appeal stated that "foreseeability, whether heightened or reduced, is tested by what the defendant knows, not what the defendant could have or should have learned" (Margaret W. v. Kelley R. (2006) 139 Cal.App.4th 141, 158, as quoted in CACI No. 1005). Knowing the particular attacker is not always required. In Vasquez (2004), the owners had no knowledge of the intruder's violent propensities, but complaints about a missing door pane, an aborted entry and assaults in other units were enough to require a $15 repair. Many websites state the rule as "knew or should have known." The court's wording in Margaret W. is narrower, and how far an owner can be charged with facts it never learned is a question a lawyer answers for each case.
Notice of a specific person
The strongest cases usually involve written reports to the landlord or manager about threats or violence by a specific person, and no meaningful response. Complaints about noise or suspected drug activity, without threats or violence, are weaker evidence that violence was foreseeable. Two cases mark the line: Castaneda v. Olsher (2007) 41 Cal.4th 1205 and Madhani v. Cooper (2003) 106 Cal.App.4th 412.
In Castaneda, the California Supreme Court said a tenant's "behavior and known criminal associations may, in some circumstances, create such a high level of foreseeable danger to others that the landlord is obliged to take measures to remove the tenant from the premises." In Madhani, a tenant made "at least six requests to the building managers for help" about a neighbor's assaults, and the Court of Appeal reversed a ruling for the landlords. Our guide to being attacked by another tenant covers this pattern.
The causation rule
Causation means the owner's failure actually contributed to the attack or the injury. In Saelzler v. Advanced Group 400 (2001) 25 Cal.4th 763, the California Supreme Court held that "the plaintiff must establish, by nonspeculative evidence, some actual causal link between the plaintiff's injury and the defendant's failure to provide adequate security measures." The Court assumed the owners had failed to keep the gates locked and to provide enough daytime guards. The plaintiff still lost, because the attackers were never identified and "could have been tenants of defendants' apartment complex, who were authorized and empowered to enter the locked security gates." She could not show it was "more probable than not" that more security would have prevented the attack.
Identified attackers
An identified attacker the owner already knew about is the clearest way to meet the causation rule in Saelzler. The Saelzler owners, the Court noted, had no "advance notice that a particular assailant was on the premises," unlike a security company that had repeatedly ignored directions to keep a specific man out (Rosh v. Cave Imaging Systems, Inc. (1994) 26 Cal.App.4th 1225). In Madhani v. Cooper (2003), the Court of Appeal held it was "up to the jury at trial, not the court on summary judgment, to decide whether it is reasonably probable installing a security camera or removing [the neighbor] from the premises or other feasible remedies could have prevented" the tenant's injuries. With a known attacker, the question becomes what a warning, a camera, a notice to leave or an eviction would have changed.
Other proof of causation
Proof of how the attacker got in, or how long help took, can also meet the causation rule. Video, signs of forced entry or a police report showing the attacker came through a specific broken door or gate ties the defect to the attack. In Sharon P. (1999), the record had "no evidence that her attacker actually used any of the darkened areas to facilitate his assault." Proof that the attacker had no key, fob or right to be there answers the problem in Saelzler. When staff watched an attack and did nothing, the question in Morris v. De La Torre (2005) 36 Cal.4th 260 was whether the failure to act "caused plaintiff to incur greater injury than he would have suffered" otherwise, so minutes and response times matter.
Evidence of notice
Records from the police, the courts and the owner's own files show what the owner was told before an attack. The owner's files, including complaints, emails, incident reports and guard logs, come through discovery, the exchange of evidence in a filed case (Code of Civil Procedure section 2031.010). The table below lists public records that California law opens to a victim or to the public, as of November 11, 2026.
| Record | What it can show | Who can get it | Law |
|---|---|---|---|
| Police calls for service to the property | The time, substance and location of each call, and the time and nature of the police response | The public, unless release would endanger a person or an investigation | Government Code section 7923.615 |
| Names, statements and diagrams in the police report of the attack | Who was involved, what the parties and witnesses said, and where it happened | The victim or an authorized representative, for the crimes the statute lists | Government Code section 7923.605 |
| Reports, photographs and 911 recordings in domestic violence, sexual assault, stalking, human trafficking and elder abuse cases | One free copy, within five working days of the request, or ten for good cause | The victim or the victim's representative | Family Code section 6228 |
| Eviction cases a landlord filed against the attacker | That the landlord was concerned enough about the person to start an eviction | A party; anyone who gives one plaintiff's and one defendant's names and the address; a resident with a party's name or the case number and proof of residency; or anyone the court allows | Code of Civil Procedure section 1161.2 |
| Civil harassment restraining orders against the attacker | That a judge found harassment by that person, and when | The protected person, and through the court file | Code of Civil Procedure section 527.6 |
Eviction and court files
An eviction case against the attacker can be hidden from an ordinary name search. An unlawful detainer case is the court's term for an eviction. Under Code of Civil Procedure section 1161.2, it is generally closed to the public unless the landlord won a judgment, either within 60 days of filing or after a trial. A civil harassment order issues only when a judge "finds by clear and convincing evidence that unlawful harassment exists" (section 527.6). If the landlord filed an eviction against the attacker, or received a copy of a protective order against that person, that is strong evidence of what the landlord knew.
The evidence clock
Some public evidence of notice can be lawfully erased within months, so the requests go out at once. A city or county department may destroy recordings of telephone and radio communications, which can include 911 calls, "after 100 days" (Government Code section 34090.6; section 26202.6 for counties). It needs approval from its legislative body and the written consent of its attorney. For police body cameras, nonevidentiary video "should be retained for a minimum of 60 days, after which it may be erased, destroyed, or recycled" (Penal Code section 832.18(b)(5)(A)). No California statute we found sets how long a private owner keeps its own camera footage; the system's settings decide. These rules were checked on November 11, 2026. Our negligent security evidence checklist lists who holds each record and how to ask for it in writing.
Security experts
A security expert is a witness who reviews a property's crime history, staffing, lighting, locks and guard records. The expert then gives an opinion on what reasonable security required and whether it would likely have stopped the attack. That opinion is only as strong as the facts under it. The California Supreme Court in Saelzler (2001), quoting Leslie G. v. Perry & Associates (1996) 43 Cal.App.4th 472, said "proof of causation cannot be based on ... an expert's opinion based on inferences, speculation and conjecture." A security expert works from records: prior calls for service, incident reports, guard post orders, patrol logs, repair work orders and the scene itself. The lawyer decides from those records whether a case needs one.
Filing deadlines
Most California injury lawsuits must be filed within two years of the injury (Code of Civil Procedure section 335.1). Some claims have more time and some have less; our negligent security deadlines guide lists each period. The deadline calculator counts the general deadlines from one date, and the dates in any one case should be calculated by a lawyer. Once fault is proved, our guide to when the attacker is mostly at fault explains how a jury divides it.
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Sources cited
- Judicial Council of California Civil Jury Instructions (CACI), 2026 edition, Nos. 1000 and 1005: courts.ca.gov
- Ann M. v. Pacific Plaza Shopping Center (1993) 6 Cal.4th 666: CourtListener
- Castaneda v. Olsher (2007) 41 Cal.4th 1205: CourtListener
- Sharon P. v. Arman, Ltd. (1999) 21 Cal.4th 1181: CourtListener
- Vasquez v. Residential Investments, Inc. (2004) 118 Cal.App.4th 269: CourtListener
- Delgado v. Trax Bar & Grill (2005) 36 Cal.4th 224: CourtListener
- Madhani v. Cooper (2003) 106 Cal.App.4th 412: CourtListener
- Saelzler v. Advanced Group 400 (2001) 25 Cal.4th 763: CourtListener
- Morris v. De La Torre (2005) 36 Cal.4th 260: CourtListener
- Code of Civil Procedure section 2031.010: california.public.law
- Government Code section 7923.615: california.public.law
- Government Code section 7923.605: california.public.law
- Family Code section 6228: california.public.law
- Code of Civil Procedure section 1161.2: california.public.law
- Code of Civil Procedure section 527.6: california.public.law
- Government Code section 34090.6: california.public.law
- Government Code section 26202.6: california.public.law
- Penal Code section 832.18: california.public.law
- Code of Civil Procedure section 335.1: california.public.law