POPULATION AND SAMPLING PROCEDURES

A population can be defined as the total number of possible units or elements that are included in the study (Gray, 2014:148). According to Dantzker and Hunter (2012:110), a population is a complete group or class from which information is to be gathered. Expressing their view, Saris and Gallhofer (2014:9) state that they believe that one possible issue that has to be considered when conducting research is to decide whether to report about the population as a whole or about a specific subgroup. Consequently, the ideal population in this research is all Detective Branch Commanders who deal with and had dealt with and investigated cases of murder, as well as all NPA prosecutors but such a number of participants would be too big and impossible for the researcher to handle, because of budget and time constraints. The researcher therefore decided on a target population.

The target population is the population to which the researcher ideally would like to generalise the results of the study (Welman & Kruger, 2000:122). Houser (2014:178) agrees and states that the target population includes all individuals or objects that are of interest to the researcher and to whom/which the study results

these Detective Branch Commanders and prosecutors are based, the researcher concluded that it would be impractical, expensive and time-consuming to conduct interviews with all of them.

By making use of and adhering to the views expressed by Welman and Kruger (2000:122) and Houser (2014:178), the researcher chose the province of KwaZulu-Natal (KZN) to generalise and interpret the results of the target population. The accounting police stations (also known as ‘cluster stations’) and NPA prosecutors in KZN were chosen because, at the time of registering this study, the researcher resided in the province of KZN, therefore the costs and time required to conduct the interviews would be reduced. KZN is also the place where the problem was identified.

The target population for this study consisted of the following:

 All Detective Branch Commanders from KZN accounting police stations. These Detective Branch Commanders are Commissioned Officers.

 All NPA prosecutors in the province of KZN attached to SCCU, situated in Durban. In SCCU, most prosecutors hold the ranks of State Advocates and Senior State Advocates.

The researcher decided to make use of sampling methods on the basis that a sample is a selection of elements from a population that is used to make a statement about the whole population, as alluded to by Blaickie (2003:161). The basic principle of sampling is that it is possible to produce accurate findings without the need to collect data from each and every member of a survey ‘population’ (Denscombe, 2010:23).

The following are summarised main advantages of sampling, as compared to the collection of data from the whole population, as described by Bless et al. (2013:98-99):

 Gathering of data from a sample is less time-consuming.

 Gathering data from a sample is less costly, since the costs of research are proportional to the number of hours spent on data collection.

 Sampling may be the only practical method of data collection.

 Sampling is a practical way of collecting data when the population is infinite or extremely large, thus making a study of all its elements impossible.

According to Blaxter, Hughes and Tight (2001:162) and Maxfield and Babbie (2012:133) there are two main groups of sampling, namely probability sampling and non-probability sampling. Blaxter et al. (2001:162-163) and Maxfield and Babbie (2012:145-153) further assert that the probability sampling approach is widely understood as a probability random sampling where every individual or object in the population of interest has an equal chance of being chosen for study, while non-probability sampling is used when the researcher lacks a sampling frame for the population in question, or where a probabilistic approach is not deemed to be necessary.

Maxfield and Babbie (2011:236-238) list types of probability sampling, as follows:

 Simple random sampling;

 Systematic sampling;

 Stratified sampling;

 Disproportionate stratified sampling; and

 Multi-stage cluster sampling.

On the other hand, Blaxter et al. (2001:162-163) and Maxfield and Babbie (2012:153-156) are of the view that the following constitute non-probability sampling:

 Convenience sampling;

 Voluntary sampling;

 Quota sampling;

 Purposive sampling;

 Dimensional sampling; and

 Snowball sampling.

The researcher chose both simple random sampling as a probability method, and purposive sampling as a non-probability sampling. These sampling methods are discussed below:

2.5.1 Simple random sampling

For the simple random sample, the participants consisted of the Detective Branch Commanders of the KZN accounting police stations. These accounting police stations were chosen because the researcher resided in the KZN province, therefore the cost and time spent on conducting interviews were reduced. The accounting police stations generally record the highest number of violent crimes, such as murder. Each accounting police station has an average of seven police stations under its control.

The Detective Branch Commanders of the accounting police stations were chosen because:

 they hold higher police ranks, such as Captains, Lieutenant-Colonels and Colonels, and are likely to have investigation experience and academic qualifications;

 they are required to do monthly inspection of case dockets to establish the progress of investigation as well as to identify problems that the investigators might have;

 they act as mentors to the investigators under their command;

 case dockets are submitted to them for their certification before going to court and vice versa; and

 in general, Detective Branch Commanders are seasoned police officers, notwithstanding the fact that some of them might not have been previously involved in the investigation of cases; however, this presumed shortcoming is negated by internal training they have to attend before being appointed as Detective Branch Commanders.

In selecting the Detective Branch Commanders, it was important for the researcher to consider that the intention of the study is to, among other things, influence the policy-makers. Consequently, individuals in strategic positions such as the

Detective Branch Commanders might provide answers to the research questions, as opposed to the investigators, who are the fieldworkers.

In order to select a simple random sample, a list of all accounting police stations in KZN was obtained to establish the sampling frame. Once the sampling frame had been established, a simple random sample was produced by assigning a single number to each element in the frame, not skipping any number in the process (Maxfield & Babbie, 2011:236).

At the time of this study there were twenty-six accounting police stations in KZN.

The names of these accounting police stations were placed in a box and ten names were selected randomly to form a sample. The following KZN accounting police stations were subsequently selected:

 Umlazi SAPS;

 Durban Central SAPS;

 Brighton Beach SAPS;

 Ladysmith SAPS;

 Eshowe SAPS;

 Newcastle SAPS;

 Plessislaer SAPS;

 Ulundi SAPS;

 Empangeni SAPS; and

 Vryheid SAPS.

In this way, each selected KZN accounting police station was represented by its own Detective Branch Commander. During the interviews, the researcher confirmed that out of ten participants, nine have academic qualifications ranging from the National Diploma: Police Administration to postgraduate degrees. All of them had attended the mandatory Detective Course and some have attended the Detective Commanders Course. In addition, at the time of the interviews, the SAPS participants collectively had more than three hundred and five (305) cumulative years of experience in the SAPS and one hundred and sixty-nine (169) years of experience as Detective Branch Commanders. The researcher believed that the

sample of participants is a good sample and that it is in line with the views of Bless and Higson-Smith (1995:87) and Blaikie (2010:185), who state that good sampling implies the following:

 A well-defined population;

 An adequately chosen sample; and

 An estimate of how representative of the whole population the sample is.

As a result, the simple random sample consisted of ten SAPS participants and is categorised in this study as Sample A.

2.5.2 Purposive sampling

The second sampling technique used in this research was the purposive sampling.

This type of sampling is also known as ‘judgemental sampling’ and it involves selecting specific elements of a target population (Hagan, 2014:117). Occasionally it may be appropriate to select a sample on the basis of our own knowledge of the population, its elements, and the nature of our research aims - in short, based on our judgement and the purpose of the study (Maxfield & Babbie, 2011:244). As a result, the purposive sampling was made up of the NPA prosecutors who are attached to the SCCU, which is situated in Durban in the province of KZN.

At the time of this study, there were fourteen prosecutors attached to the SCCU, and five of them were selected to participate in this research. The reason for this number is purely mathematical, as it is a fair fraction of 30% of SCCU prosecutors in Durban. The SCCU prosecutors were selected because the “prosecution-led investigation model” is currently used in the SCCU offices across the country as an effective investigative approach to commercial crimes. The SCCU, in cooperation with the CCU, adopted this model in response to the increasing number of commercial crime cases.

These SCCU prosecutors have experience in the execution of the prosecution-led investigation methodology. As reflected in paragraph 1.9 of Chapter 1, which deals with the limitations of the study, the NPA offered only three prosecutors to be interviewed. However, the researcher believes that this sample was still good as, at

Advocates who had more than thirty years combined experience in the prosecution-led investigation model. In addition, these NPA participants hold Bachelor of Laws (LL B) degrees, which is the minimum requirement to be appointed as a State Advocate. The purposive sample of the NPA thus consisted of three NPA participants and is categorised in this study as Sample B.

Furthermore, the researcher made use of the purposive sampling method to conduct interviews with each participant representing the police departments of Malawi and France. Before interviews could be conducted, requests were sent to each country to provide the researcher with details of each senior police officer who had more than ten years’ experience in criminal investigation. The researcher considers ten years’ experience as reasonable and sufficient for having sound judgement in respect of criminal investigation methodology. The reason for this request was to ensure that the researcher conducts interviews with relevant representatives of police departments who are knowledgeable of the criminal investigation procedures used in their respective countries. Both Malawian and French police representatives were senior officers, with more than twenty years and twenty-three years of experience in the criminal investigation, respectively. They both belong to the specialised units, namely: Homicide Section (Malawi Police Service) and Police Judiciare (French National Police). Accordingly, the researcher categorised these participants as follows:

 Representative of Malawi Police Service: Sample C.

 Representative of French National Police: Sample D.

In total, this means that in this study the simple random sample and purposive samples consisted of fifteen participants.