title: Spatial signatures and mental maps: Using offenders’ activity locations to enhance geographic profiling for crime investigations

authors: Curtis-Ham, Sophie

subjects: Crime location choice

abstract: In crime investigations, geographic profiling involves inferring information about ‘whodunit’ from information about where and when the crime occurred. Such inferences are possible because people usually commit crime in places they know, rather than seeking opportunities elsewhere. The ‘spatial signature’ of a crime location thus reflects the ‘mental map’ of the offender: the locations they are familiar with from their everyday activities, such as where they live, work, go to school or visit family and friends. Previous empirical research suggests that people are more likely to commit crime near some activity locations in their mental map than others. However, these differences have not been accounted for in theory or in geographic profiling methods—particularly methods that infer the most likely suspect to have committed a crime, given the proximity of their activity locations to the crime. This thesis aimed to enhance geographic profiling by developing, validating, and applying a theoretical model that explains how people’s different activity locations influence their crime locations.

To achieve this aim, I first drew on existing theoretical and empirical literature to propose a theoretical model that identifies the attributes of people’s activity locations that influence whether they will commit crime nearby and the psychological mechanisms through which this influence occurs. Next, I tested hypotheses derived from the model to add to its empirical support, using New Zealand Police data on approximately 60,000 offenders who committed burglaries, robberies and extra-familial sex offences between 2009 and 2018. This national dataset included details of the offenders’ crime locations and their pre-crime activity locations such as home addresses, family members’ home addresses, schools, and the locations of prior crimes and other police interactions. I then applied the theoretical model in a new geographic profiling algorithm: the Geographic Profiling: Suspect Mapping and Ranking Technique (GP-SMART). For a given crime, GP-SMART predicts suspects’ probability of committing the crime given the proximity of their activity locations to the crime and the attributes of those activity locations that influence whether they will commit crime nearby—as described in the theoretical model—and prioritises the suspects accordingly. I tested GP-SMART’s accuracy by investigating how often it placed the actual offender among the top ranked suspects.
The theoretical model proposed that people are more likely to commit crime in locations where they have reliable knowledge that is relevant to the future crime. Attributes of people’s activities—such as their frequency and similarity to the future crime—affect the development of reliable and relevant knowledge. The empirical tests confirmed that offenders were generally more likely to commit crime closer to the kinds of activity locations that people visit more frequently (e.g., home versus family homes) or likely to impart more relevant knowledge about crime opportunities (e.g., prior crimes versus prior victim or witness location). They were also more likely to commit crime near prior activity locations that would generate both reliable and relevant knowledge, than near prior activity locations lower on either or both dimensions. By accounting for the theoretically salient attributes of suspects’ activity locations, GP-SMART ranked the offender at or near the top of the suspect list at rates exceeding chance and those produced by baseline methods—approximating existing algorithms—that use proximity alone.

This thesis makes significant theoretical, methodological and practical contributions. The theoretical model explicitly extends crime pattern theory, and the empirical studies add to the evidence base for this extension and core tenets of both the environmental criminology and investigative psychology theoretical approaches to geographic profiling. The police data included a wider range of activity locations than used in past crime location choice studies based on administrative data, and the findings highlight their utility for signalling offenders’ mental maps. Indeed, the size of the dataset required developing a novel method for sampling when using Discrete Spatial Choice Modelling—a major methodological contribution to the growing discrete crime location choice literature. But of most significance in light of the motivation for this thesis, the GP-SMART results demonstrate that enhancing geographic profiling by incorporating the attributes of people’s various activity locations that influence their crime locations, could help solve crime in practice.

text: Spatial signatures and mental maps: Using offenders’ activity locations to enhance geographic profiling for crime investigations In crime investigations, geographic profiling involves inferring information about ‘whodunit’ from information about where and when the crime occurred. Such inferences are possible because people usually commit crime in places they know, rather than seeking opportunities elsewhere. The ‘spatial signature’ of a crime location thus reflects the ‘mental map’ of the offender: the locations they are familiar with from their everyday activities, such as where they live, work, go to school or visit family and friends. Previous empirical research suggests that people are more likely to commit crime near some activity locations in their mental map than others. However, these differences have not been accounted for in theory or in geographic profiling methods—particularly methods that infer the most likely suspect to have committed a crime, given the proximity of their activity locations to the crime. This thesis aimed to enhance geographic profiling by developing, validating, and applying a theoretical model that explains how people’s different activity locations influence their crime locations.

To achieve this aim, I first drew on existing theoretical and empirical literature to propose a theoretical model that identifies the attributes of people’s activity locations that influence whether they will commit crime nearby and the psychological mechanisms through which this influence occurs. Next, I tested hypotheses derived from the model to add to its empirical support, using New Zealand Police data on approximately 60,000 offenders who committed burglaries, robberies and extra-familial sex offences between 2009 and 2018. This national dataset included details of the offenders’ crime locations and their pre-crime activity locations such as home addresses, family members’ home addresses, schools, and the locations of prior crimes and other police interactions. I then applied the theoretical model in a new geographic profiling algorithm: the Geographic Profiling: Suspect Mapping and Ranking Technique (GP-SMART). For a given crime, GP-SMART predicts suspects’ probability of committing the crime given the proximity of their activity locations to the crime and the attributes of those activity locations that influence whether they will commit crime nearby—as described in the theoretical model—and prioritises the suspects accordingly. I tested GP-SMART’s accuracy by investigating how often it placed the actual offender among the top ranked suspects.
The theoretical model proposed that people are more likely to commit crime in locations where they have reliable knowledge that is relevant to the future crime. Attributes of people’s activities—such as their frequency and similarity to the future crime—affect the development of reliable and relevant knowledge. The empirical tests confirmed that offenders were generally more likely to commit crime closer to the kinds of activity locations that people visit more frequently (e.g., home versus family homes) or likely to impart more relevant knowledge about crime opportunities (e.g., prior crimes versus prior victim or witness location). They were also more likely to commit crime near prior activity locations that would generate both reliable and relevant knowledge, than near prior activity locations lower on either or both dimensions. By accounting for the theoretically salient attributes of suspects’ activity locations, GP-SMART ranked the offender at or near the top of the suspect list at rates exceeding chance and those produced by baseline methods—approximating existing algorithms—that use proximity alone.

This thesis makes significant theoretical, methodological and practical contributions. The theoretical model explicitly extends crime pattern theory, and the empirical studies add to the evidence base for this extension and core tenets of both the environmental criminology and investigative psychology theoretical approaches to geographic profiling. The police data included a wider range of activity locations than used in past crime location choice studies based on administrative data, and the findings highlight their utility for signalling offenders’ mental maps. Indeed, the size of the dataset required developing a novel method for sampling when using Discrete Spatial Choice Modelling—a major methodological contribution to the growing discrete crime location choice literature. But of most significance in light of the motivation for this thesis, the GP-SMART results demonstrate that enhancing geographic profiling by incorporating the attributes of people’s various activity locations that influence their crime locations, could help solve crime in practice.

year: 2022

title: Reflecting on teacher development in technology education: Implications for future programmes

authors: Compton, Vicki

subjects: programme evaluation

abstract: This paper reflects on the outcomes of teacher professional development programmes in technology education. These programmes were based on a model which emphasised the importance of teachers developing an understanding of both technological practice and technology education. Two different programmes have been developed and trialed in the New Zealand context. They are the Facilitator Training programme, and the Technology Teacher Development Resource Package programme. This paper will focus on the outcomes of these programmes. The Facilitator Training programme was a year long programme, and ran in 1995 and 1996. It involved training a total of 30 educators – 15 each year, from all over New Zealand. The Resource Package was trialed in 14 schools over a 3–6 month period in 1996. The evaluations indicate the successful nature of these programmes and the usefulness of the model as a basis for the development of teacher professional development in technology education.
The programmes reported on in this paper were developed and evaluated as part of two New Zealand Ministry of Education contracts held by the Centre for Science, Mathematics and Technology Education Research.

text: Reflecting on teacher development in technology education: Implications for future programmes This paper reflects on the outcomes of teacher professional development programmes in technology education. These programmes were based on a model which emphasised the importance of teachers developing an understanding of both technological practice and technology education. Two different programmes have been developed and trialed in the New Zealand context. They are the Facilitator Training programme, and the Technology Teacher Development Resource Package programme. This paper will focus on the outcomes of these programmes. The Facilitator Training programme was a year long programme, and ran in 1995 and 1996. It involved training a total of 30 educators – 15 each year, from all over New Zealand. The Resource Package was trialed in 14 schools over a 3–6 month period in 1996. The evaluations indicate the successful nature of these programmes and the usefulness of the model as a basis for the development of teacher professional development in technology education.
The programmes reported on in this paper were developed and evaluated as part of two New Zealand Ministry of Education contracts held by the Centre for Science, Mathematics and Technology Education Research.

year: 1998

title: Investigation of in vitro diabetic inflammation and  treatment with Piper excelsum tea extract

authors: Harvey, Savannah

subjects: Piper excelsum

abstract: Induction of inflammation through hyperglycaemia and adiposity has been shown to contribute to the pathogenicity of type 2 diabetes (T2D). The pro-inflammatory cytokine, tumour necrosis factor α (TNF-α) was the first cytokine found to bridge the connection between the immune system and T2D. This was found due to its increased production in the disease state. TNF-α has specifically been linked to the onset of insulin resistance in T2D models. Evidence has shown that heat shock protein 60 (HSP60) may also play a role as a danger signal for the immune system as it can result in the induction of inflammation. Currently, there are no pharmaceutical options for T2D patients which target inflammation. Tea made from the leaves of kawakawa (Piper excelsum) has been used for many generations by Māori as a traditional rākau rongoā (traditional medicine) to treat a range of ailments including inflammation. The aim of this project was to investigate the modulation of inflammation using a commercially available kawakawa tea in human cancer cells in vitro. 

This project involved measuring the growth rate, cytotoxicity, TNF-α production and HSP60 expression upon exposure to three treatments: high glucose, lipopolysaccharide (LPS) or kawakawa tea extract (KTE).

This study showed that a high concentration of KTE (1000 µg/mL) inhibited cell growth in both HEPG2 and HeLa cell lines. Cells treated with this concentration also showed typical morphological signs of apoptosis. Cytotoxicity testing confirmed that there was a significant (p <0.05) decrease in mitochondrial dehydrogenase activity for this treatment which confirmed the cells were likely dying through apoptosis. Over a course of 24-hours three LPS treatments were found to be cytotoxic. These were the 10 ng/mL, 10 µg/mL, and 100 µg/mL concentrations of LPS. After 48-hours all treatments apart from 100 µg/mL KTE treatment were also found to be cytotoxic. The cytotoxicity for these treatments was either due to a reduction in mitochondrial dehydrogenase activity (infers mitochondrial stress) or increased lactate dehydrogenase (LDH) release from cells (infers necrotic cell death). These cytotoxicity experiments allowed for identification of which concentrations should be selected or removed for future experiments. 

Cytotoxicity levels were taken into consideration and experiments were run investigating the induction of TNF-α using enzyme-linked immunosorbent assays (ELISA). Issues regarding negative readings from samples arose which resulted in protocol changes and extensive trouble shooting. It was found that extended exposure times were required to attenuate a positive result from the positive control, LPS. 

HSP60 expression was also measured for human cells exposed to high glucose and KTE treatments. No change in HSP60 expression was detected. However, 24-hour LPS exposure resulted in a significant increase in HSP60 expression compared to the control for the 100 ng/mL LPS treatment. Two concentrations were investigated; 100 ng/mL LPS and 100 µg/mL LPS which resulted in 1.4- and 2.1-fold increases compared to the control, respectively.

Overall, no conclusion could be drawn regarding the modulation of inflammation by KTE. However, this study was able to identify the effect the tea has on human cancer cell growth and the nature of cytotoxicity the tea poses to the cells. It is recommended to continue this research exploring different kawakawa tea blends and using alternative in vitro cell lines and whole animal models.

text: Investigation of in vitro diabetic inflammation and  treatment with Piper excelsum tea extract Induction of inflammation through hyperglycaemia and adiposity has been shown to contribute to the pathogenicity of type 2 diabetes (T2D). The pro-inflammatory cytokine, tumour necrosis factor α (TNF-α) was the first cytokine found to bridge the connection between the immune system and T2D. This was found due to its increased production in the disease state. TNF-α has specifically been linked to the onset of insulin resistance in T2D models. Evidence has shown that heat shock protein 60 (HSP60) may also play a role as a danger signal for the immune system as it can result in the induction of inflammation. Currently, there are no pharmaceutical options for T2D patients which target inflammation. Tea made from the leaves of kawakawa (Piper excelsum) has been used for many generations by Māori as a traditional rākau rongoā (traditional medicine) to treat a range of ailments including inflammation. The aim of this project was to investigate the modulation of inflammation using a commercially available kawakawa tea in human cancer cells in vitro. 

This project involved measuring the growth rate, cytotoxicity, TNF-α production and HSP60 expression upon exposure to three treatments: high glucose, lipopolysaccharide (LPS) or kawakawa tea extract (KTE).

This study showed that a high concentration of KTE (1000 µg/mL) inhibited cell growth in both HEPG2 and HeLa cell lines. Cells treated with this concentration also showed typical morphological signs of apoptosis. Cytotoxicity testing confirmed that there was a significant (p <0.05) decrease in mitochondrial dehydrogenase activity for this treatment which confirmed the cells were likely dying through apoptosis. Over a course of 24-hours three LPS treatments were found to be cytotoxic. These were the 10 ng/mL, 10 µg/mL, and 100 µg/mL concentrations of LPS. After 48-hours all treatments apart from 100 µg/mL KTE treatment were also found to be cytotoxic. The cytotoxicity for these treatments was either due to a reduction in mitochondrial dehydrogenase activity (infers mitochondrial stress) or increased lactate dehydrogenase (LDH) release from cells (infers necrotic cell death). These cytotoxicity experiments allowed for identification of which concentrations should be selected or removed for future experiments. 

Cytotoxicity levels were taken into consideration and experiments were run investigating the induction of TNF-α using enzyme-linked immunosorbent assays (ELISA). Issues regarding negative readings from samples arose which resulted in protocol changes and extensive trouble shooting. It was found that extended exposure times were required to attenuate a positive result from the positive control, LPS. 

HSP60 expression was also measured for human cells exposed to high glucose and KTE treatments. No change in HSP60 expression was detected. However, 24-hour LPS exposure resulted in a significant increase in HSP60 expression compared to the control for the 100 ng/mL LPS treatment. Two concentrations were investigated; 100 ng/mL LPS and 100 µg/mL LPS which resulted in 1.4- and 2.1-fold increases compared to the control, respectively.

Overall, no conclusion could be drawn regarding the modulation of inflammation by KTE. However, this study was able to identify the effect the tea has on human cancer cell growth and the nature of cytotoxicity the tea poses to the cells. It is recommended to continue this research exploring different kawakawa tea blends and using alternative in vitro cell lines and whole animal models.

year: 2021