Rates of recorded crime have been falling in many countries in Western Europe, including Scotland, since the early 1990s. This marks the reversal of a trend of increasing levels of crime seen since the 1950s. Despite this important recent change, most analyses of the ‘crime drop’ have focused on recorded crime or victimisation rates aggregated to national or regional level. It is little known how patterns of offending or conviction have changed at the individual level. As a result it is not known how the crime drop is manifest in changing offending or conviction rates, or how patterns of criminal careers have changed over this period. The aim of this thesis is to explore trends in convictions across a number of criminal careers parameters – the age-crime curve, prevalence and frequency, polarisation and conviction pathways – over the course of the crime drop in Scotland. The results presented here are based on a secondary analysis of the Scottish Offenders Index, a census of convictions in Scottish courts, between 1989 and 2011. Analysis is conducted using a range of descriptive statistical techniques to examine change across age, sex and time. Change in the age-crime curve is analysed using data visualisation techniques and descriptive statistics. Standardisation and decomposition analysis is used to analyse the effects of prevalence, frequency and population change. Trends in conviction are also examined between groups identified statistically using Latent Class Analysis to assess the polarisation of convictions, and trends in the movement between these groups over time provides an indication of changing pathways of conviction. This thesis finds a sharp contrast between falling rates of conviction for young people, particularly young men, and increases in conviction rates for those between their mid-twenties and mid-forties, with distinct periods of change between 1989- 2000, 2000-2007 and 2007-2011. These trends are driven primarily by changes in the prevalence of conviction, and result in an increasingly even distribution of convictions over age. Analysis across latent classes shows some evidence of convictions becoming less polarised for younger men and women but increasingly polarised for older men and women. Similarities in trends analysed across latent classes between men and women of the same age suggest that the process driving these trends is broadly similar within age groups. Increases in conviction rates for those over 21 are explained by both greater onset of conviction and higher persistence in conviction, particularly between 1998 and 2004. The results of this thesis suggest that explanations of the crime drop must have a greater engagement with contrasting trends across age and sex to be able to properly explain falling conviction rates. These results also reinforce the need for criminal careers research to better understand the impact of recent changes social context on patterns of convictions over people’s lives. The distinct periods identified in these results suggest a potential effect of changes in operation of the justice system in Scotland leading to high rates of convictions in the early 2000s. However, the descriptive focus of this analysis and its reliance upon administrative data from a single country mean this thesis cannot claim to definitively explain these trends. As a result, replication of this research in another jurisdiction is encouraged to assess whether trends identified are particular to Scotland.

During the 1990’s the world witnessed a crime drop throughout all categories of crime. Many researchers have sought to seek an explanation for this drop; however, there has been a lack of concrete findings to fully explain this phenomenon. The purpose of this study is to explore a further reasoning as to why this drop occurred, specifically throughout the United States. An unexplored factor to explain this phenomenon is the increase of household computer ownership during the 1990’s. During this decade, household computers and the internet became prevalent throughout the nation. This study utilized secondary data from the Uniform Crime Report and the United States Current Population survey, with support from routines activities theory, to answer the research question to find if there was a correlation between household computer use and the crime drop. The results for this study found that there was a positive correlation between household computer ownership, household internet ownership, and all realms of crime. With this, it is important to note that the social trend of household computer ownership is not the only reasoning for this phenomenon.

Despite previous research in this area, the relationship between immigration and crime in the United States remains ambiguous and surrounded by misconceptions. However, recently, scholars have suggested that, despite the claims of policy-makers and popularized sociological theories, large immigrant concentrations may be linked with lower as opposed to higher crime rates. In the past, research in this area has been imprecise due to it its implementation of cross-sectional analyses for a limited selection of geographic regions. However, through the implementation of time-series procedures and the use of annual data for metropolitan statistical areas during the 2005–2010 periods, the present study evaluates the impact of changes in immigration concentration on changes in crime rates, both violent and non-violent. These multivariate analyses specify that violent and property crime rates generally decreased as metropolitan areas experienced increases in their proportion of immigrants. These results confirm the hypothesis that the recent decline in crime is partially due to increases in the concentration of foreign-born individuals.

Building on a growing body of research linking an opportunity framework to drops in acquisitive crime and most recently, acquisitive violence, the present thesis extends this framework to the downward trajectory of nighttime economy violence in England and Wales, during the phenomenon of the crime drop. Using secondary data analysis of the Crime Survey for England and Wales, the rate of stranger and acquaintance violence within the night-time economy is found to have halved between 1995 and 2011/12; mirroring the dramatic declines experienced by other crime types within England and Wales, and more widely across other westernised countries. Disaggregating this overarching trend by offence and victim characteristics reveals a reduction in alcohol-fuelled, common assaults between young males, occurring in and around the drinking venues of the night-time economy, and during weekends, to be the main driver of the drop. Boden, Fergusson and Horwood (2013) argue that to date there is limited knowledge surrounding the nature of alcohol-related violence. The present research explores the nexus between alcohol and violence through a situational lens. The opportunistic nature of night-time economy violence is identified through offenders' choice of tools (weapons) and selection of targets, as well as the clustering of violence along certain spatial, temporal, and individual, dimensions. The opportunity structure of night-time economy violence is established using multivariate modelling techniques designed to isolate the role of opportunity in assault-victimisation, and resultant severity, from the personal characteristics of the actors involved. Measures of a 'risky lifestyle', characterised by an increase in routine activities that take respondents away from the safety of the home, are found to be the strongest predictors of assault victimisation-risk across every available sweep of the survey. A significant shift in population lifestyle - namely a significant net decline in routine engagement with the drinking venues of the night-time economy, as well as a shift in the gender and age composition of drinking venue patronage - co-varies with the decline in night-time economy violence. However, residual effects of respondents' socio-demographic characteristics on victimisation-risk, after mediating for differences in lifestyle, presents violent victimisation in the night-time economy as a result of a process by which personal traits interact with criminogenic environments. Personal characteristics, however, are weaker in their prediction of offence severity in the night-time economy. Rather, the present research supports a collection of research identifying the context of violence to be the strongest predictor of violent dispute escalation (Brennan, Moore & Shepherd, 2010; Marcus and Reio, 2002).