Weapons, drugs and crime: the Australian experience


To make Australia a safer place to live, legislative reforms have been introduced that seek to restrict the number of weapons in the community. Reforms have centred on knives carried in public places, and on firearm ownership and possession. The focus on knives is of particular importance, as they are commonly used weapons. For example, knives and sharp instruments were used in 32 percent of homicides in 2003-04 (Mouzos 2005). Knives were involved in 28 percent of assaults and 52 percent of armed robberies in 2003 (ABS 2004). Using data collected as part of the Drug Use Monitoring in Australia (DUMA) program, this paper explores the link between weapons, drugs and crime, with a specific focus on weapon ownership and possession.

Previous research has explored the use of particular weapons in crime and the characteristics of weapons offences, but the reasons for owning and carrying weapons, and the sources of those weapons have not been examined. Nor have there been many studies examining the possible link between drug use and weapons, in particular firearms (Sheley 1994). Using data collected as part of the DUMA program, this paper examines the extent to which police detainees self-reported:

  • whether and why they owned particular weapons
  • where they obtained their weapons
  • their use of weapons in crime
  • their illicit drug use and criminal history.

Such data have the potential to inform:

  • crime reduction policy, by providing an indication of the form and size of the problem
  • policing strategies, for stemming supply
  • street-level policing, in terms of likelihood of encountering armed individuals
  • police training (see also Makkai & McGregor 2002).

Links between weapons and drugs

Illicit drugs have been linked to weapons, particularly firearms, in a number of ways, including that:

  • violence, with or without weapons, can be an integral part of the drug trade
  • dependent drug users may commit crimes to finance their drug habit, possibly with weapons
  • drug users may commit crimes of violence when under the influence of drugs, possibly with weapons
  • firearms and other weapons may be exchanged for drugs and drugs for firearms (Oscapella 1998).

A review of the international literature reveals that not all of the links identified are equally supported by research. For example, occasional drug users who are not involved in the drug trade generally do not possess or use firearms more than people who do not use drugs (Sheley 1994). While dependent users may resort to the use of weapons and firearms when committing crimes to get money for drugs, research suggests this is not the most common reason for property crime but that the principal link is the role of firearms in the illegal drug trade including protecting shipments of drugs, intimidating customers or competitors, enforcing debts, resolving disputes, eliminating competition, and punishing informants (Nadelmann 1991; Oscapella 1998).


The DUMA program operates across seven sites in Australia on a quarterly basis. It involves voluntary interviews with police detainees, and the provision of a urine sample (see Makkai 1999 on the methodology). In addition to standard questions on drug use and offending behaviour, a different questionnaire addendum is administered to detainees each quarter. The addenda cover topics of specific concern to policy-makers and law enforcement (for example, drug driving, amphetamines, violence in the home). An addendum concerning weapons was administered to detainees in the third quarter of 2001, the fourth quarter of 2002 and the first quarter of 2004 (n=2,323). As the Elizabeth, Adelaide and Brisbane sites did not join DUMA until 2002, they are excluded from the 2001 data. While some of the questions varied across the three surveys, for the most part they were consistent.

Of the 3,291 adult detainees approached for interview in the quarters in which the weapons addendum was administered, 2,323 provided responses to addendum questions (a rate of 71%). This paper outlines the results of responses to these three addenda.

Weapon ownership

Across all sites, 40 percent reported that they had at some time in their lives, owned or possessed a knife as a weapon. Just over a quarter of the detainees reported that they had owned or possessed a handgun, sawn-off shotgun or rifle, or other firearm in their lifetime (26%; Table 1). Reported lifetime ownership is usually higher than more recent ownership, but the general pattern of weapon ownership was not markedly different over the two timeframes: a higher proportion reported owning a knife than a firearm in the past 12 months (36% and 16% respectively). Handguns and shotguns/rifles were the firearms of choice both in the year before interview, and in lifetime ownership. Many of the detainees who reported owning a firearm in the past 12 months also reported owning a knife (72%).

In July 2001 five percent of the Australian adult population had a firearms licence (Mouzos 2002), whereas 20 percent of detainees in 2002 reported owning a firearm in the past year. The proportion is much higher than the general population, and very few of the police detainees reported holding a firearms licence (10%). This is not surprising, as a prior criminal record would automatically exclude a person from legally obtaining a firearms licence. Research on the licensing and registration status of firearms used in homicide also finds a very low rate of compliance with firearms licensing legislation (Mouzos 2002, 1999; Mouzos & Segrave 2004).

Table 1 : Weapon ownership
  Past 12 months Over the lifetime
Number Percent Number Percent
n/a = question not asked of detainees.
Note: Percentages do not total 100 and numbers do not total n because detainees could own multiple firearm and weapon types.
Source: AIC, DUMA collection 2001-2004 [computer file]
Any weapon 547 40 1123 48
Multiple weapons 175 13 599 26
Knife 485 36 922 40
Any firearm 220 16 609 26
Sawn-off shotgun or rifle 117 9 393 17
Handgun 133 10 357 15
Other firearm 68 5 283 12
Martial arts weapon n/a n/a 476 20
Other weapon n/a n/a 427 18
(N) (1365)   (2323)  

Trends in DUMA sites in all three surveys (n=1,312) show that the proportion of detainees reporting that they had ever owned a knife and/or a firearm has decreased. In 2001, 51 percent of detainees reported ever owning a knife compared with 35 percent in 2004, although this significant relationship is not necessarily strong (.13). Similarly, in 2001, 32 percent of detainees reported ever owning a firearm compared with 22 percent in 2004 (significant association=.09). While both knife and firearm lifetime ownership declined over the three years, there was a slight increase in the proportion of detainees who reported owning a firearm in the year before interview (12% in 2001, 20% in 2002 and 19% in 2004: significant association =.10). There was a significant, but not strongly related increase (association=.09) in reported recent knife ownership (from 33% in 2001 to 40% in 2004).

The factors behind changes in patterns of weapon ownership over time are not clear. The decline in lifetime ownership of knives and firearms may reflect legislative changes designed to reduce weapon ownership. Stricter laws aim to limit weapon availability and harsher penalties aim to deter individuals from illegal ownership. Opportunities to own weapons legally over the lifetime may be reduced because of increased deterrence and/or decreased weapon availability. Thus for detainees interviewed most recently there may have been fewer opportunities for lifetime ownership than for detainees interviewed in 2001. The increase over time in detainees' recent firearm ownership indicates that this type of explanation cannot account for all changes over time, however. Other factors include environmental factors (e.g. changed policing strategies, such as the introduction of stop and search powers for police) or differences between detainees interviewed (e.g. their regular criminal activities). More detailed investigation is required.

When asked about how many knives or firearms detainees owned during the past 12 months, some detainees reported very large numbers; for example, one had owned 400 knives. Excluding such outlier cases (those reporting a value greater than two standard deviations above the overall mean: 3% of knife owners; 6% of firearm owners), recent knife owners reported owning an average of four knives, and an average of two firearms were possessed by recent firearms owners.

Reasons for owning weapons

Reasons are infrequently explored by research into weapon use. The DUMA weapons addendum asked detainees their main reasons for owning a knife or firearm. Owning a weapon for protection and/or self defence was one of the most common reasons offered by the detainees who owned a knife (47%) or firearm (44%) although this is not considered a genuine reason under the National Firearms Agreement (Mouzos 1999). Hunting, however, is considered a legitimate reason, and a quarter (25%) of the police detainees recently possessing firearms cited this reason. Twenty percent of detainees who owned knives gave other reasons for ownership, including ownership of collections for display purposes, or for use in fishing. Although small in number, eight percent of recent firearm owners (less than 1% of all detainees) reported that they owned a firearm for use in the drug trade, and seven percent said their firearms were for use in other criminal activity. Proportionally fewer recent knife owners said they had knives for the drug trade (4%), or for other criminal activity (2%), but given the higher level of knife ownership, the overall proportions were similar. Irrespective of the type of weapon owned, very few detainees (1% each of knife and gun owners) reported ownership as part of being in a gang.

International data

The reasons offered for firearm ownership by Australian detainees are similar to those provided by arrestees in the United Kingdom. In an equivalent research program there, 36 percent of arrestees self-reported ever owning or having easy access to a gun, and 24 percent indicated they had owned a firearm in the past 12 months (Bennett 2000). Protection/self-defence followed by hunting/target shooting were the main reasons for firearm ownership by these arrestees. In the United States many detainees, both juvenile and adult indicated that guns and violence were acceptable methods for obtaining respect and protection, and for seeking revenge (Riley 1996).

Usual supply and source of weapons

Given that the majority of firearms reportedly owned by the police detainees were not legally owned, important questions for both policy-makers and law enforcement concern the usual means of supply and sources of weapons.

The majority of detainees who reported owning knives or firearms in the past year indicated they had bought their weapons mostly through illegitimate sources (66% for knife owners; 60% for firearms owners). Fourteen percent of knife owners and 13 percent of firearms owners obtained their weapons by other means, including inheriting the weapon or obtaining it as a gift. One in twenty knife owners and one in ten firearms owners reported trading for their weapons. A similar proportion of knife (6%) and firearms (7%) owners reported stealing their weapons.

Detainees were also asked about their usual sources of supply. Irrespective of the type of weapon, the most common source was a family member or friend (see Table 2). A higher proportion of detainees who reported owning a firearm indicated obtaining it from the street (21%) or a drug dealer (7%), than knife owners (8% and 1% respectively).

Table 2 : Usual source of weapons
  Knife Firearm
Number Percent Number Percent
Note: Does not sum to 100 due to rounding. Exceeds number of individual knife/firearm owners because detainees could list multiple usual sources.
Source: AIC, DUMA collection 2001-2004 [computer file]
On the street 41 8 46 21
Drug dealer 3 1 14 7
Family member/friend 142 29 113 51
Private sale 4 1 11 5
Army disposal store 119 24 1 0
Knife/gun shop 44 9 23 10
Pawn shop 12 2 0 0
Other retail 96 19 6 3
Other 41 8 5 2
(Total) (502)   (222)  

Only 10 percent of all recent firearms owners obtained their firearm from a specialist gun shop. Questions concerning the legality of purchases were not asked, but further analyses of the data suggest that these firearms were bought from sources other than licensed dealers. Of the 130 detainees who reported buying firearms and also provided information regarding where they were bought, the majority sourced from a family member or friend (50%), or on the street (22%). In contrast, the 318 detainees who had bought knives reportedly sourced them from army disposal stores (35%), other retailers (24%), or specialist knife shops (12%).

While just over a third of detainees reported owning a knife in the past 12 months, 21 percent of recent knife owners (about 4% of all detainees) indicated they carried the knife every day, with a further 10 percent (2% of total) reporting carrying a knife most days. Sixteen percent of detainees reported owning a firearm in the past 12 months, with five percent of these (about 0.5% of the sample) reporting carrying a firearm every day. Eight percent of firearm owners (less than 1% of the total) reported carrying the firearm most days.

Overall, 36 percent of recent knife owners (n=175) and 45 percent of recent firearms owners (n=98) indicated that they never carried their weapons. Of these, 11 percent of recent knife owners and 31 percent of recent firearms owners indicated that their weapons were for the purposes of hunting or target shooting. Interestingly 34 percent and 42 percent of each respective group stated that these not-carried weapons were for self-defence or protection.

Carrying knives and firearms in public places is prohibited in most Australian jurisdictions, yet these results highlight that almost a third of knife owners and 14 percent of firearm owners who come to the attention of police regularly carry these weapons. To avoid detection and raising alarm by displaying the weapon in public view, detainees reported concealing their weapons in a number of ways. Knife owners most commonly conceal their weapon in their pocket (25%), or tuck it into their boots or clothing (19%). A further nine percent conceal it in their backpack or handbag.

Fewer firearms owners conceal the firearm in their pocket (5%). While some handguns are easily concealed, shotguns and rifles (even shortened) are not. Firearms are mainly concealed in boot/pants/clothing (22%), or in a holster (15%).

Use of weapons to commit crime

Sixteen percent of all detainees reported using a weapon to commit crime at some time in their lives (data were not collected on the types of crimes committed with these weapons). Nine percent reported using knives, seven percent firearms, and five percent had used some other weapon to commit a crime (see Figure 1). One in fifty used a syringe to commit a crime. Similar proportions were found in the United Kingdom sample, with 14 percent of arrestees ever using a knife to commit an offence, and five percent ever using a firearm to commit an offence (Bennett 2000).


Figure 1: Types of weapons used by detainees to commit crime at some time in their lives (n=2,323)[see attached PDF for graph]


Table 3 presents a comparative analysis of the characteristics of detainees who used a knife, firearm, or both to commit a crime, and detainees who did not use a weapon to commit a crime. Significant points to note:

  • detainees who used a knife to commit crime are younger than detainees who used a firearm, both a knife and firearm, or no weapon (association=0.14)
  • detainees who used a knife to commit crime are less likely to be in full-time employment than detainees in the other groups (association=0.08)
  • detainees who had not used a weapon to commit a crime were less likely to have been arrested in the past year than detainees who used a weapon to commit a crime (association=0.14)
  • detainees who did not use a weapon to commit a crime were less likely than detainees who used a weapon (regardless of the weapon used) to have been in prison in the past year (association=0.16), or to have been charged with a violent offence in the past year (association=0.17).
Table 3 : Characteristics of police detainees by weapon type used to commit crime
  Knife Firearm Knife + firearm No crime with weapon
Number Percent Number Percent Number Percent Number Percent
Note: Only includes detainees who reported ever owning a weapon. Weapon categories include cases where detainees reported using the weapon(s) in question in addition to other weapons (including syringes). Criminal history refers to any charges in the category in question, calculated from charges linked to current detention and self-reported arrests in the year preceding interview.
Source: AIC, DUMA collection 2001-2004 [computer file]
Male 116 84 60 88 84 92 858 87
Under 30 years of age 108 78 39 57 60 66 568 57
Completed year 10 of education 74 54 40 58 59 65 494 50
Working full-time 20 14 12 18 20 22 255 26
Criminal history
Arrested in the past 12 months 100 73 47 69 61 67 528 53
In prison in the past 12 months 44 32 23 34 40 44 205 21
Charged with a violent offence in the past 12 months 71 51 22 32 43 47 283 29
Charged with a property offence in the past 12 months 70 51 40 59 50 55 419 42
Charged with a drug offence in the past 12 months 19 14 18 26 23 25 188 19
(Total) (138)   (68)   (91)   (990)  

Considering only detainees who provided a sample for urinalysis (knives only n=130; firearms only n=60; firearms & knives n=76; no weapon n=816) a number of differences emerged in prior drug use patterns across the groups of detainees (see Table 4). The results indicate that:

  • detainees who did not use a weapon to commit a crime were less likely than those who did to commit a crime (regardless of the weapon used) to self-report any drug use (association 0.16) or multiple drug use (association=0.15) in the previous 30 days and previous 12 months
  • detainees who did not use a weapon to commit a crime were also less likely to test positive (through urinalysis) to any drug (association=0.14) and multiple drug use (association=0.11).
Table 4: Prior drug use among police detainees by weapon type used to commit crime
  Knife Firearm Knife + firearm No crime with weapon
Number Percent Number Percent Number Percent Number Percent
Note: Only includes detainees who reported ever owning a weapon. Weapon categories include cases where detainees reported using the weapon(s) in question in addition to other weapons (including syringes). 'Any' and 'multiple' drug categories include only the four drug types examined here. Urinalysis provides evidence of the use of that class of drug in the period up to 30 days before testing. Drug detection times vary as a function of a range of factors, including the type of drug (Milner, Mouzos & Makkai 2004). Urinalysis totals derived from those detainees within each weapon group who also provided a sample for urinalysis.
Source: AIC, DUMA collection 2001-2004 [computer file]
Self-reported use in the past year
Any drug 124 90 63 93 88 97 780 79
Multiple drugs 105 76 54 79 73 80 541 55
Cannabis 110 80 53 78 83 81 672 68
Methylamphetamine 88 64 45 66 66 73 492 50
Cocaine 23 17 16 24 28 31 143 14
Heroin 49 36 31 46 39 43 221 22
(Total) (138)   (68)   (91)   (990)  
Any drug 96 80 48 83 65 92 554 71
Multiple drugs 42 35 23 40 35 49 223 28
Cannabis 84 70 35 60 57 80 450 57
Methylamphetamine 38 32 27 47 31 44 239 31
Cocaine 4 3 4 7 4 6 19 2
Heroin 18 15 12 21 18 25 103 13
(Total) (120)   (58)   (71)   (783)  

Discussion and conclusion

At the beginning of this report the theoretical links between weapons and illicit drugs were outlined. DUMA data could examine only the first three links. Results show that weapons may be used as part of the drug trade. Detainees reportedly owned weapons, particularly firearms, for use in the drug trade and for protection/self-defence. Of the detainees who had recently owned weapons, nearly half of knife and firearm owners said they did so for protection or self-defence.

In relation to the second and third links, DUMA data indicate significant associations between prior drug use and weapon use in crime. Regardless of the weapon used, detainees who used a weapon to commit a crime self-reported higher levels of illicit drug use and were more likely to test positive to drugs than detainees who did not use a weapon to commit crime.

There are a number of significant findings in this report. Nearly half of police detainees reported owning a weapon of some sort in their lifetime and around 40 percent reported weapon ownership in the year before interview. Both lifetime knife ownership and lifetime firearms ownership decreased between 2001 and 2004. Legislative reform designed to limit weapon availability and regulate weapon ownership may be behind this, but clearly has not impacted on a subset of detainees because the proportional ownership of firearms in the year before interview increased over the same period. Most detainees who owned firearms were unlicensed and their weapons were obtained through informal rather than authorised channels.

Approximately two out of three detainees who had owned a firearm or owned a knife in the past year had bought their weapons. Knife owners who had purchased their weapons tended to buy from retailers, whereas firearm owners tended to buy from family or friends, or on the street. A subset of detainees purchased firearms from informal and presumably illegal vendors.

The illicit trade in firearms is a challenge for law enforcement because some individuals appear undeterred by the penalties associated with their illegal trade and ownership. Weapon exchange is often between family and friends, presenting a further difficulty for law enforcement.

Sizeable minorities of recent firearm and knife owners do not carry their weapons. By implication, these weapons are stored elsewhere. If not stored securely or in compliance with legislation, they may be misused by others, or subject to theft - especially firearms (see Mouzos 2005; Mouzos & Sakurai forthcoming).

Prior to the administration of the weapons addendum in the DUMA questionnaire, there were no other data available on weapons and their use in crime, especially in relation to illegal ownership and possession. Given the importance of this issue and the paucity of information on it, since mid-2005 weapons questions have been included in the standard DUMA questionnaire. This quarterly information allows the analysis of trends and patterns of weapons and illicit drugs use, and the identification of changes in a timely manner. This strategic focus contributes to better informed policy, law enforcement and research.


All URLs were correct at May 2006

About the authors

Dr Jenny Mouzos is a senior research analyst and manager of the Crime Monitoring Program at the AIC.

Dr Maria Borzycki is a research analyst in the same area.