Mapping drug offenders

Criminality inspired by Class A drug abuse is a problem that faces forces nationwide. Ascertaining the level of threat within communities, as well as finding where the offenders live and use is an ongoing challenge. In Lancashire, analysts have been working on mapping drug abuse in some unexpected and original ways.

An ambulance is called to an overdose victim. On arrival, the paraphernalia of heroin use leads the paramedics to administer an urgent dose of naloxone, a drug that counters the effect of heroin on the brain. Each incident such as this is recorded, so how could analysts use this information to tackle problematic drug markets?

Claire Wood, an analyst at Lancashire Constabulary, explained how the department came to be using such unusual data sets to map drug markets in Lancashire.

“Many forces have tried drug mapping and will have taken a different stance, but in Lancashire we centred on Class A problematic drug markets,” she said.

The background

“We tried to use the situational crime prevention model,” said Mrs Wood. “We wanted to target what limited resources we have on these areas of greatest need. We needed to identify what our hotspots were.”

By identifying hotspots, the analysts were able to design specifically targeted responses. The analytical team recognised quickly the futility of trying to use only police data, in particular possession and supply data.

“Supply data tends to show us areas of police activity,” said Mrs Wood. Test purchasing operations are limited in their span; activity cannot target all of Lancashire at the same time and therefore, “is no use as a blanket tool for geographic analysis”.

Possession offences data also provides little insight into problematic drug areas, instead showing areas of police operations. Inevitably, using this data led to the analysts finding hotspots around police stations. The analysts realised that to accurately map problematic drug markets, they would need help from other agencies.

“We can’t tackle drug crime in isolation,” said Mrs Wood. “If we are going to tackle it effectively, then it needs to be a localised response and to combine enforcement, treatment and prevention.”

Why use geographical mapping?

Utilising mapping to help combat drug related crime has many benefits. All crimes that take place can be put into a geographical context. However the data is collected, whether by GPS systems used by other agencies or manually entered onto a police database, all incident data can be geographically analysed.

It also enables the force to target high crime areas, which they hope will lead to a lessening of drug problems across the Lancashire area. “By tackling open markets, it’s hoped that we can impact on all the drug markets across Lancashire,” said Mrs Wood.

Mapping is also helpful in identifying drug markets that are not easily visible to the public or police. The fact that Lancashire encompasses coastal towns such as Blackpool exacerbates the problem. These holiday destinations have a constantly shifting population, which causes difficulty to officers identifying where drug problems exist. Other markets that affect locations away from residential areas can also be difficult to identify.

Mapping can provide more accurate pictures than those created by the perceptions of the public and officers. Mrs Wood cited the 2001 study by Ratcliffe and McCulloch on repeat victimisation of burglary. The study asked police officers in their areas to map what they thought was their visual perception of the burglary problem. They then mapped, with GIS, the actual burglary problem, and found vastly differing results.

“The problem was much more defined than the officers thought,” explained Mrs Wood. “Quite often, our view of where drug problems are may not be accurate.”

Rejected data sets

Lancashire worked to develop the most relevant data sets for drug market mapping. They examined types of data and analysed whether they would be rel