Dementia is not a specific disease. It describes a group of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person’s ability to perform everyday activities. Alzheimer’s disease accounts for 60 to 80 percent of dementia cases. 

Eighty-eight percent of Alzheimer’s disease patients undergo behavioral changes. The most common changes are agitation, anxiety, irritability, disinhibition, delusions, and hallucinations. Delusions are often paranoid or persecutory (i.e. delusions that someone was stealing from them or other abuses). The patients incorrectly perceived a non-existent attack or misidentified someone they knew as an imposter or a stranger.

One-third of all Americans over the age of 65 own a gun and an additional 12% live in a household where another person owns a gun. In 2010, there were 4.8 million persons diagnosed with Alzheimer’s, In 2050, the number of persons with Alzheimer’s is expected to reach 13.8 million. When a family member is diagnosed with dementia, securing or removing firearms from the patient’s home is often not a consideration.
At some point, all persons with irreversible dementia will lose their ability to safely handle a firearm. Since, individuals with dementia do not have the ability to the determine when their condition makes them dangerous, family members typically must be vigilant to cognitive and behavioral changes.
Death by suicide occurs most often in the early stages of dementia. Suicide is now the 10th leading cause of death in the United States. Nearly 45,000 Americans killed themselves in 2016. It is predominantly men who use guns to commit suicide, and men are much less likely to seek help than women. As the disease progresses, the risk of death shifts from self-harm to harm to family and caregivers.
The use of firearms requires complex mental skills that are usually lost in early dementia and continue to worsen as the disease progresses. Loss of one’s ability to consistently recognize familiar people and places, an increase in physically aggressive behavior, disorientation and fear may place families and caregivers at risk. “Delusions of home intruders or confusion about the identity of persons in their lives may lead persons with dementia to confront family members, health aides, or other visitors. Access to a firearm may increase the potential for injury or death in such a situation.”
Gun removal is the best option but depending on the fluctuating moods of the patient, once removed, they guns can be re-purchased or the “theft” could be reported to the police. Removing ammunition and locking weapons in a gun safe are possible solutions.
If these precautions do not work, Red-Flag laws also known as Extreme Risk Protection Orders or Gun Violence Restraining Orders permit families and law enforcement to petition a court to temporarily suspend a person’s access to firearms if there is documented evidence that an individual is threatening harm to themselves or others. After a family member files a petition, the court holds a hearing and determines whether the person poses a serious threat of violence to themselves or others. The judge can issue an order restricting access to firearms for up to one year and can also refer the person in crisis for evaluation to ensure they get the help they need. Once a petition is filed, the court notifies the subject and a hearing is held. If the evidence of a threat is upheld by a judge, the order is put in place for one year and can be renewed annually should circumstances warrant. The subject may request one hearing a year to rescind the order. 
The Red-Flag statutes are law in six states and have been modestly successful in reducing suicide. However, this law could significantly mitigate the risk posed by that small proportion of legal gun owners who, at times, may pose a significant danger to themselves or others. When a gun owner has a dementia diagnosis, a Red-Flag law could be a life-saver.

Agitation, broadly defined to include non-compliance, refusal to cooperate with the caregiver, obstinence, resistance, crying, kicking, and being “hard to handle.”
Anxiety is defined as worried or frightened behavior displayed for no apparent reason, or tense and fidgety behavior.
Irritability is rapid emotional fluctuations between frustration and impatience.
Mega, Cummings… Neurology, “The spectrum of behavioral changes in Alzheimer’s disease,”
Healy, Melissa, As more older Americans struggle with dementia, what happens to their guns? Los Angeles Times, 5/11/18.
Guns and Dementia, Susan Jeffrey 7/21/2014
Betz, McCourt, Annals of Internal Medicine, Firearms and Dementia, 8 May 2018,
Swanson, Duke Law & Contemporary Problems, Implementation and Effectiveness of Connecticut’s Risk-Based Gun Removal Law: Does It Prevent Suicides? 2017