Table 1.

Basic demographics & findings.

Study	Place	Dates	Offender age	Older homicide offenders	Male homicide offenders	Female homicide offenders	Key findings
Aliustaoĝlu et al. (2011)	Turkey	2000−2005	60 years and above	83	N/A	N/A	Voluntary manslaughter in this population was statistically more common in healthy subjects compared to those subjects diagnosed as mentally ill (p < 0.02). Healthy cases used firearms more frequently compared to those diagnosed as mentally ill (p = 0.004)
Block (2013)	Chicago	1965−2000	60 years and above	476	422	54	Elderly male offenders were more likely than younger adult male offenders to have killed an intimate partner. Intimate partner homicide: 84 men; 28 women. 338 males killed acquaintance (21.9%), friend (16.6%), stranger (12.1%), son (6.5%), neighbour (4.4%), sexual rival (3.6%), roommate (3.0%), son-in-law (2.7%), customer (2.7%) and landlord (2.4%). 26 women killed friend (19.2%), acquaintance (11.5%), neighbour (11.5%), neighbour in an apartment building (7.7%), stranger (7.7%) and cousin/son-in-law/daughter-in-law/child being watched/roommate/patient/tenant/landlady/business partner (3.8% each)
Bourget et al. (2010)	Quebec	1992−2007	65 years and above	27	25	2	The homicide was frequently followed by the suicide of the perpetrator. Several victims had pre-existing medical illnesses, indicating that the offences may have been committed by individuals who were caregivers to chronically ill spouses. At the time of the offense, most of the perpetrators had a mental illness, usually depressive disorder, but few had received psychiatric help. Most of the homicides (n = 25, 93%) took place in the victims’ homes
Cheung et al. (2016)	New Zealand	July 2007−December 2012	65 years and above	4	4	0	All perpetrators were men; three had been farmers. One case occurred in the context of an underlying psychiatric illness (psychotic depression in BPAD). Firearms were used in three cases. Two cases were categorised as spousal/consortial subtype, one case as filicide-suicide, and one case as siblicide-suicide. The prospect of major social upheaval in the form of losing their homes was present in all four cases
Fazel et al. (2007)	Chicago	1965−1995	60 years and above	443	393	50	Elderly killers were more likely to be white and to commit suicide afterwards. Their victims were more likely to be spouses, female and aged over 60 years
Goetting (1992)	Detroit	1982−1983	55 years and above	45	40	5	Older offenders are more likely than younger offenders to kill in a private residence. Most homicides arose from domestic discord and from petty quarrels between friends, neighbours and acquaintances. There was evidence of prosecutorial leniency in the determination of criminal processing outcomes
Hunt et al. (2010)	England and Wales	1997−2004	65 years and above	62	58	4	Perpetrators aged 65 and over were more likely to use strangulation/suffocation, and the victim was more often female and a family member or spouse. Older perpetrators had high rates of affective disorders and were more likely to be mentally ill at the time of the offence
Kratcoski (1990)	Cuyahoga County, Ohio; Cincinnati, Ohio; Detroit, Michigan	1970−1985	60 years or older	179	146	33	The victim and assailant were known to each other in 89% of all cases. In 25% of cases, one spouse was killed by the other. 74% of homicides occurred in the home. All homicide-suicide incidents reported (9%) involved a suicide by a husband after he murdered his wife. 44% of elderly homicide offenders were under the influence of alcohol and both the victim and offender were drinking in 40% of cases. Firearms were the cause of death in 86% of cases and stabbing occurred in 11% of cases
Malphurs and Cohen (2005)	Florida	1 Jan 1998−31 Dec 1999	55 years and above	20	20	0	Homicide-suicide perpetrators displayed significantly more domestic violence or were caregivers for their wives, compared to matched suicide controls. 65% of perpetrators had reported depressed mood. 40% of homicide-suicide perpetrators were caregivers for their wives. All perpetrators were married men who used a firearm
Myers et al. (2017)	United States	1976−2012	55 years and above	32	32	0	Murders by older sexual homicide offenders accounted for only 0.5% of United States sexual homicides. Over two-thirds of older sexual homicide offender victims were aged 40 years or more, and one third were aged 55 years or more
Overshott et al. (2012)	United Kingdom	1 April 1996−31 March 2001	60 years and above	47	43	4	Homicides perpetrated by older people typically involved a man killing his partner in an impulsive manner. The most common method was by using a sharp instrument (34%), followed by the use of a blunt instrument (26%). The use of firearms was rare (11%). Perpetrators over 65 years were significantly more likely to kill a current or former spouse/partner and less likely to kill an acquaintance. 44% of perpetrators over 65 years suffered from depression at the time of the offence, whereas the rates of schizophrenia and alcohol dependence were low
Putkonen et al. (2010)	Finland	1995−2004	60 years and above	25	22	3	Homicide offenders aged 60 years or older were diagnosed less often than gender-matched younger homicide offenders with drug dependence and personality disorders and more often with dementia and physical illnesses. The mean Psychopathy Checklist-Revised total scores as well as factor and facet scores were lower in the 60 or older age group
Reutens et al. (2015)	New South Wales	1993−2010	55 years and above	70	57	13	The proportion of male offenders and rates of firearm use were similar to other age groups. 12 of the 14 homicides using guns occurred outside the metropolitan area. Older offenders were more likely to have cognitive impairment or psychotic illnesses. Victims were more likely to be female and in a domestic relationship with the offender
Shiferaw et al. (2010)	Geneva	1 Jan 1956−31 Dec 2005	62 years and above	3	3	0	Three cases of homicide-suicide perpetrators were aged over 55 years of age. In all three cases, the victim was a spouse or intimate partner
Verzeletti et al. (2014)	Brescia County, Italy	Jan 1987−Dec 2012	55 years and above	6	6	0	Six cases of homicide-suicide perpetrators were over 55 years of age. Five of the victims were the wives of the offender and one was the lover. Firearms were used in three of the homicides, whereas firearms were used in five of the suicides. All the homicides occurred in the home. Significant illnesses were experienced by the older couple in four of the cases and morbid jealousy was the motive in one case