Observer Based Techniques

Course manual 2023/2024

Course content

In forensic sciences a lot of techniques are observer based, meaning that they are mainly based on the comparison and evaluation of forensic traces by observation, not by measurement. The course Observer Based Techniques deals with the pros and cons of the numerous fields of forensic comparisons. During the course forensic techniques such as tool and ballistic marks, handwriting, fingerprints et cetera will be addressed.
Apart from focusing on the similarities between the different observer based techniques, their evidential value in case work is assessed, as well as recent criticism on these techniques. The latter includes the lack of data on error rates and the effect of context information on the expert’s decision making process. The requirement for setting-up a database to be able to objectify forensic examinations will be highlighted.
We will elaborate on two specific fields of interest, namely: fingerprints and ballistics.
For fingerprints we will go from the steps of collecting, visualising and assessing the quality of the fingerprint to identification. Furthermore the new developments and their potential in the field will be addressed.
For ballistics the essentials of trace comparisons and the reconstruction of a crime scene by use of physics will be discussed. This will prepare the students to work on a mock ballistic crime scene and to act as an expert in that examination. From a combination of their own findings, observer based comparisons and fictitious lab results events have to be reconstructed and a final overview of the findings of the crime scene has to be laid down.

Study materials

Other

• Handouts of the presentations

Objectives

• 1. Criticise the evidential value of a specific technique in forensic case work for a given forensic field
• 2. Evaluate the potential value of crime scene information, ballistic traces and terminal characteristics for a ballistic reconstruction.
• 3. Explain the possibilities and pitfalls of the available and developmental techniques associated with fingerprint examination and their role in identification
• 4. Evaluate the different types of biasing information and their possible influence on the interpretations of forensic comparisons
• 5. Set-up a procedure to minimise the risk of the sources of bias
• 6. Evaluate the requirements and criteria for database set-up to objectify the evidential value forensic comparisons
• 7. Analyse and interpret the output of a LR-based database comparisons
• 8. Evaluate and combine the different results of investigations and comparisons to support or falsify a previously formulated scenario

Teaching methods

• Lecture
• Computer lab session/practical training
• Fieldwork/excursion
• Presentation/symposium
• Self-study

This course consists of lectures, tutorials and practicals.

In general, a topic will start with a lecture about (a part) of the theory after which you will receive either an individual or a team assignment. Presentations on assignments will be given on the next course day. The assignments will be given to illustrate the different concepts addressed during the module. In addition to the lectures, tutorial and practicals the student is expected to read the indicated literature. Due to scheduling some weeks of the course will be more demanding of the students’ time than others and the amount of literature will vary as well. We recommend students to study the schedule and plan the necessary hours for reading the literature at the beginning of the course.

The tutorial and all practicals are mandatory for the scheduled teams. To be able to offer every team the same material, the practicals will be given multiple times during a day. Because of limited time and space, each team should come to the appropriate scheduled session (cannot be exchanged).

Learning activities

Attendance

This programme does not have requirements concerning attendance (OER part B).

Additional requirements for this course:

Attending all scheduled education activities is strongly advised. By doing so, you actively contribute to a lively learning community and significantly improve your chances of successfully completing the course. The designated mandatory activities play a crucial role in achieving the course objectives and are essential for your overall progress.

Additional requirements for this course:
Students are expected to participate in the (online) classes, but the lectures are not mandatory. The student presentations, tutorials and practicals are compulsory for all students. When unable to attend please inform the instructor in good time to figure out a possible solution.

Assessment

1a. Presentation
The oral presentations for the different forensic fields, bias in casework and the set-up of a database will be assessed on a group basis by a numerical grade given by instructors.

1b. Tutorials
A real case example will be assessed and their will by a computer tutorial coupled to the lectures on terminal ballistics.

2. Practicals
The mock crime scene will be assessed on multiple levels;
1) presentation and justification of prioritisations of investigations
2) quality of examination request form
3) final written assignments.

3. Written Examination
The final exam of this course will be a written examination based on the content covered during the lectures, tutorials, practicals and literature. The exam will be assessed on an individual basis.

All components will be graded on a scale from 1 to 10, with a maximum of one decimal after the point. These grades are used to calculate the final grade. In order to pass the course, all components and the final grade have to be sufficient, i.e. at least a five and a half. When a student has not fulfilled this requirement, the examiner will register the mark ‘did not fulfill all requirements’ (NAV) whether or not the averaged grade is sufficient.

The components will be weighted as follows:

1. Presentations and tutorials combined (20%, where the case example assignment and the tutorial terminal ballistics will constitute for 5 of the total 20%)
2. Practical (30%)
3. Written examination (50%)
   
   The final grade will be announced at the latest 15 working days after the final course activity (January 16th). Between this date and 35 working days after the final course activity (February 13th), a post-exam discussion or inspection moment will be planned. This will be announced on Canvas and/or via email

The components will be weighted as follows:

1. Presentations and tutorials combined (20%, where the case example assignment and the tutorial terminal ballistics will constitute for 5 of the total 20%, group)
2. Mock crime scene practical (30%, group)
3. Written examination (50%, individual)

Table of specification: the relation between the Learning Outcomes (LO) of the course, the assessment components of the course and the Exit Qualifications (EQ) of the Master’s Forensic Science (described in the Introduction in the Course Catalogue)

Assignments

The presentation

During the course there will be a few oral presentations for which every student is expected to participate by either presenting or by the answering of questions.

The tutorials

There will be two tutorials during the course. A real case example will be assessed and their will by a computer tutorial coupled to the lectures on terminal ballistics.

Assignment case example
The assignment focusing on a real case example will be assessed by the instructor and by other teams (peer review). Each grade will be given by a conversion of a verbal scale to numerical (not delivered=0, unsatisfactory=4, satisfactory=6, good=8, excellent=10). The final grade for the assignment will be based on both grades. The instructor’s grading will count for 70% of the final grade and the students’ grading for 30%.

Tutorial terminal ballistics
The possible grade for the tutorial will be given by a conversion of a verbal scale to numerical (not delivered=0, unsatisfactory=4, satisfactory=6, good=8, excellent=10).

Assignment fingerprint approaches

The assignment on approaches in fingerprint evaluation will be assessed during the final presentation by the instructor. The presentation will also be part of the assessment. The grade will be given by a conversion of a verbal scale to numerical (not delivered=0, unsatisfactory=4, satisfactory=6, good=8, excellent=10).

The practicals

The mock crime scene will be assessed on multiple levels;
1) presentation and justification of prioritisations of investigations
2) quality of examination request form
3) final written assignments.

Level 1: A numerical grade will be given by the instructors.
Level 2: A verbal scale will be given by the instructors. The possible grade for the assignment will be given by a conversion of a verbal scale to numerical (not delivered=0, unsatisfactory=4, satisfactory=6, good=8, excellent=10).
Level 3: For each report a numerical grade will be given by the instructors. This grades will be multiplied by the number of persons in a team. The team members will divide the grades between each other based on their personal contributions with a maximum of minus 2 points from the given grade by the instructors.

Final grade = level 1 (35%) + level 2 (15%) + level (50%)

Fraud and plagiarism

The 'Regulations governing fraud and plagiarism for UvA students' applies to this course. This will be monitored carefully. Upon suspicion of fraud or plagiarism the Examinations Board of the programme will be informed. For the 'Regulations governing fraud and plagiarism for UvA students' see: www.student.uva.nl

Course structure

Timetable

The schedule for this course is published on DataNose.

Last year's student feedback

In order to provide students some insight how we use the feedback of student evaluations to enhance the quality of education, we decided to include the table below in all course guides.

Contact information

Coordinator

• dr. E.J.A.T. Mattijssen