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Attacked by another tenantYour written reports can prove the landlord knew.

A California landlord can be responsible when one tenant attacks another, usually when the landlord or manager knew that person was dangerous and did nothing meaningful. The key proof is written reports of threats or violence by that person. The law may require a landlord to act, up to eviction, when violence by that tenant is highly foreseeable.

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Josh Kohanim, Esq.Written and reviewed by Josh Kohanim, Esq., California Bar No. 328609 · Published · Reviewed

In this guide

This page was checked against the statutes and cases it cites on November 11, 2026. It is general information about California law, not advice about any one case. Our negligent security page explains these claims in every setting, and our premises liability page covers injuries from unsafe property conditions.

The landlord's duty to tenants

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.

For tenants, the California Supreme Court put the rule this way in Castaneda v. Olsher (2007) 41 Cal.4th 1205: a landlord "generally owes a tenant the duty, arising out of their special relationship, to take reasonable measures to secure areas under the landlord's control against foreseeable criminal acts of third parties." The questions are what the landlord knew before the attack and which reasonable step it skipped.

Reports of threats or violence

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. The two key cases are Castaneda v. Olsher (2007) 41 Cal.4th 1205 and Madhani v. Cooper (2003) 106 Cal.App.4th 412.

A report carries weight when it names the person, describes a threat, an assault or a weapon, gives the date, and reaches the manager or owner in writing. Repeated reports, and a manager's promise to handle the problem followed by nothing, show more. In Castaneda, the 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."

Notice to the landlord

Notice means what the landlord or its manager actually knew before the attack. Castaneda v. Olsher says a landlord judging an existing tenant "can rely on his or her own observations or those of a property manager and, where the circumstances make these reliable, on complaints of the other tenants." In both Castaneda and Madhani v. Cooper, the courts treated complaints to the manager as notice to the landlord. The notes to CACI No. 1005 also quote a Court of Appeal: "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). A dated, written report shows what management was told, and when.

Repeated reports and no action

In Madhani v. Cooper (2003) 106 Cal.App.4th 412, a tenant was repeatedly shoved, blocked and berated by a neighbor in her building. She asked the managers for help at least six times. They promised to "take care of the situation" and did nothing, and the neighbor later pushed her down the stairs. The Court of Appeal reversed summary judgment for the landlords. It held that 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" her injuries. The Castaneda court later described Madhani as holding the landlord had a duty to evict the assaultive tenant if necessary.

Warning signs that fell short

In Castaneda v. Olsher (2007) 41 Cal.4th 1205, the tenant lost. A 17-year-old resident of a mobilehome park was shot as a bystander in a gang confrontation involving the occupants of a home across the street. Complaints that the neighbors' dog growled at a family, a report of broken car windows, and men whistling at his sister, even with the manager's belief that the neighbors were gang members, did not show the high foreseeability needed for a duty to evict. The Supreme Court noted that "No one had reported that" the neighbors "or their guests had used, displayed or possessed a gun at the mobilehome park." Reports of violence, threats or weapons are what was missing.

Steps short of eviction

A landlord with reports of a tenant's threats or violence has tools short of eviction. Madhani v. Cooper named two: warning the tenant "she would be evicted if she persisted in her assaultive behavior," and a security camera on the staircase where most of the aggression happened. Others include a written notice to correct a lease violation, which California's Tenant Protection Act requires before a curable violation can end a tenancy (Civil Code section 1946.2(c)), offering the threatened tenant a transfer to another unit, and pointing the victim to a stay-away order under Code of Civil Procedure section 527.6, as the Madhani court noted. Castaneda v. Olsher adopted a sliding scale: "the less foreseeable the harm, the lower the burden a court will place on a landlord." Cheaper steps can be owed on less warning than eviction.

Eviction of a dangerous tenant

A landlord may be required to act, up to eviction, when violence by that tenant is highly foreseeable. Castaneda v. Olsher said so while warning that eviction "cannot be considered a minimal burden" and that courts have recognized a duty to evict "only in cases where the tenant's behavior made violence toward neighbors or others on the premises highly foreseeable." Madhani v. Cooper applied that duty to a neighbor's repeated assaults. In Hawkins v. Wilton (2006) 144 Cal.App.4th 936, owners were allegedly warned that a tenant, who also worked as their manager and night security guard, carried loaded guns, used methamphetamine and had pulled a gun on another tenant. The Court of Appeal reversed summary judgment for the owners because their motion did not defeat the claims as pleaded. It did not decide that the owners were liable.

Eviction rules in California

California law gives landlords the means to remove a tenant who endangers neighbors. A tenant who commits or permits a nuisance on the premises, or uses them "for an unlawful purpose," can be served a three-day notice to quit (Code of Civil Procedure section 1161(4)). Under the Tenant Protection Act, at-fault just cause includes a nuisance and "Criminal activity by the tenant on the residential real property, including any common areas" (Civil Code section 1946.2(b)(1)(C) and (F)). Where a local just-cause ordinance adopted on or before September 1, 2019, or a later and more protective one, covers the building, the local ordinance applies instead (Civil Code section 1946.2(i)). A lawyer should check which rule covered the building at the time.

Lock changes after a threat

A threatened tenant can demand a fast lock change in writing. Under Civil Code section 1941.5, when a person who is not a tenant of the same unit is alleged to have committed abuse or violence against the tenant, the landlord must change the locks at its own expense "not later than 24 hours after" the tenant gives a written request with documentation. The documentation can be a protective order, a police report, or another record that reasonably verifies the abuse or violence. Section 1941.6 covers a restrained person who lives in the same unit, with a court order excluding that person. For leases signed on or after January 1, 2011, if the landlord misses the 24 hours, the tenant may change the locks and the landlord must reimburse the cost within 21 days. These statutes require a lock change, not a general promise of safety.

A protective order as notice

If the landlord received a copy of a protective order, that is strong evidence of what it knew. A tenant who asks for a lock change, or ends a lease early under Civil Code section 1946.7, often gives the landlord a copy of the order or a police report, and that copy names the person who is the threat. An order issued after a hearing carries more weight than a petition or a temporary order. A civil harassment order issues only when a judge finds "by clear and convincing evidence that unlawful harassment exists" (Code of Civil Procedure section 527.6(i)(1)). Keep proof of the date the landlord or manager received the order.

Drug activity and noise complaints

Complaints about noise or suspected drug dealing, without threats or violence, are weaker evidence that an attack was foreseeable. Castaneda v. Olsher quoted another court: "A landlord is not obliged to institute eviction proceedings whenever a tenant accuses another tenant of harassment." A landlord can serve a three-day notice on a tenant who uses a unit "for an unlawful purpose" (Code of Civil Procedure section 1161(4)), but a power to evict is not the same as a duty to evict. A landlord may have to act when a tenant's behavior makes violence toward neighbors highly foreseeable (Castaneda v. Olsher (2007)). Drug activity alongside reported threats, assaults or weapons is a different case.

Records to keep

Keep every dated written complaint you sent about the person, and every reply. That includes emails, letters, texts to the manager, tenant portal messages and work orders, with the dates showing. Screenshot portal messages now, because a portal account can close when a tenant moves out. Also keep police report numbers, a copy of any protective order and proof the landlord received it, any lock change request, photos, and the names of neighbors who complained about the same person. If the manager answered by phone, write down the date and what was said.

Public records that fade

Some public records about earlier incidents disappear on a schedule. A city or county department may destroy 911 and dispatch recordings after 100 days (Government Code sections 34090.6 and 26202.6), and state guidance lets police erase routine body camera video after 60 days (Penal Code section 832.18). A tenant who lives in the building can see an eviction case the landlord filed against the attacker, even one closed to the public, with a party's name or the case number and proof of residency (Code of Civil Procedure section 1161.2(a)(1)(C)). Our negligent security evidence checklist lists who holds each record and how to ask for it.

The attacker's share of fault

In California, a jury can assign part of the fault to the attacker. Each defendant pays only its own share of noneconomic damages, such as pain and emotional distress (Civil Code section 1431.2), and a Court of Appeal has applied that rule to a bar whose patron was assaulted by a third person (Weidenfeller v. Star & Garter (1991) 1 Cal.App.4th 1). Economic damages, such as medical bills and lost earnings, are not divided this way. Our guide to when the attacker is mostly at fault explains how the split works.

Building security defects

Not every attack by a neighbor turns on what was known about that neighbor. A broken entry door, a dark stairwell or an unlocked gate can matter too. California requires working dead bolts, window locks and common entry locks, and a cheap repair can be owed on slight warning (Vasquez v. Residential Investments, Inc. (2004) 118 Cal.App.4th 269). The injured tenant must still show that the missing step more likely than not would have prevented the attack or reduced the harm (Saelzler v. Advanced Group 400 (2001) 25 Cal.4th 763). Our guide to what a landlord must do about crime covers locks, lighting, cameras and guards.

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. Our negligent security deadlines guide lists each period, including the longer period for a sexual assault on someone else's property, and our deadline calculator helps you count the days. The dates in any one case should be calculated by a lawyer.

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Sources cited

Frequently asked questions

Can I sue my landlord if another tenant attacked me in California?
Yes, in some cases. A California landlord owes tenants a duty to take reasonable measures against foreseeable crime in areas it controls (Castaneda v. Olsher (2007), as quoted in CACI No. 1005). A claim usually turns on whether you or others reported that tenant's threats or violence to the landlord or manager, in writing, and nothing meaningful was done. You must also show that a reasonable step would likely have prevented the attack or reduced the harm.
Is the landlord responsible if the manager knew a neighbor was dangerous and did nothing?
The landlord can be. In Madhani v. Cooper (2003) 106 Cal.App.4th 412, a tenant asked the managers for help with a neighbor's assaults at least six times, and nothing was done. The Court of Appeal held that a jury, not the judge, should decide whether a security camera or removing the neighbor could have prevented her injuries. Reports to an on-site manager count as notice to the landlord.
Does a California landlord have to evict a dangerous tenant?
Only when violence by that tenant is highly foreseeable. In Castaneda v. Olsher (2007) 41 Cal.4th 1205, the California Supreme Court said courts recognize a duty to evict only where the tenant's behavior made violence toward neighbors highly foreseeable, because eviction is not a minimal burden. Cheaper steps, such as a written warning, a lease violation notice or a camera, can be owed on less warning.
Can a landlord be liable for violence connected to another tenant's drug activity?
Usually not on suspected drug activity alone. The question is whether the landlord knew facts that made violence by that person foreseeable, such as reported threats, assaults or weapons. Complaints about noise or suspected dealing, without threats or violence, are weaker evidence that violence was foreseeable. Drug activity alongside reported threats or weapons is a different case.
What does a landlord have to do when one tenant harasses another?
It depends on the harassment. For harassment based on a protected characteristic, such as race, religion or disability, California's Civil Rights Department says "Housing providers must act quickly to correct and end harassment by another tenant when they knew or should have known about it, and where they have the power to correct it" (Cal. Code Regs., tit. 2, section 12010(a)(1)(C)). For threats or violence of any kind, the negligence rules on this page apply.
Can I sue both the attacker and the landlord?
Yes. The person who attacked you can be sued for assault and battery, and the landlord can be sued for negligence if it failed to take a reasonable step it owed. A jury can assign fault to each. The landlord pays only its own share of noneconomic damages, such as pain and emotional distress (Civil Code section 1431.2), while economic damages, such as medical bills, are not divided that way.
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