Forensic medicine as a medical specialty. Types of forensic medical examinations and expert reports

Forensic medicine applies medical knowledge to the law, in both civil and criminal matters. It has several branches, among them forensic pathology, clinical forensic medicine, psychiatric assessment, forensic toxicology and forensic entomology. Examinations are made on living persons, on the dead (at the scene of death and at the medico-legal autopsy) and on written data. Their findings are set out in statements and expert reports, which must be accurate, impartial and capable of being defended in court.

Forensic medicine is the branch of medicine in which medical principles and knowledge are used for the purposes of the law, both civil and criminal. Its task is the application of medical knowledge in the administration of law and justice.

The word "forensic" comes from the Latin forensis, meaning "of the forum". The forum was the meeting place where civic and legal matters were discussed by people with public responsibility.

Forensic medicine works in two kinds of legal proceedings. Criminal cases concern the relationship between the state and the individual, and include offences against the person such as murder, assault, grievous bodily harm and rape. The prosecution must prove its case beyond reasonable doubt, and if it cannot, the defendant is acquitted. Civil cases concern disputes between individuals, such as alleged negligence, and most remedies are financial. The standard of proof is lower: a fact is established if it is more likely than not to have happened, which is proof on the balance of probabilities.

Doctors are bound by the same general laws as everyone else, and by any additional rules specific to their profession. A doctor may be charged with a criminal offence, sued in a civil court, or called as a witness to a criminal act and asked to give evidence about it.

Forensic medicine is divided into branches, each with its own kind of work.

Clinical forensic medicine is the branch of medicine that involves an interaction among law, the judiciary and the police, and it generally involves living persons. Its practitioners are known as forensic physicians. A forensic pathologist generally does not deal with living individuals, and a forensic physician generally does not deal with the deceased. Some doctors work in both the clinical and the pathological aspects of forensic medicine, as is the practice in Bulgaria.

Forensic medical examinations are made on three subjects: living persons, the dead, and written data. The examination of the dead covers the scene of death as well as the body.

Clinical forensic medicine examines living people in the cases listed above. The typical tasks are the medico-legal examination in rape cases, the determination of age, and the assessment of permanent disability, which is used for compensation. The forensic physician records the history given and the findings at the time of the examination, and these contemporaneous notes form the basis of any later statement or report.

At the scene of death the forensic examiner records the relationship of the victim to the surroundings and estimates the post-mortem interval where it can be done at the scene.

The investigation of a death aims to:

• determine the cause and the manner of death
• identify the deceased if the identity is unknown
• determine the time of death and of the injury
• collect evidence from the body that can prove or disprove an individual's guilt or innocence, and confirm or deny the account of how the death occurred
• document the injuries, or their absence
• deduce how the injuries occurred
• document any natural disease present
• determine or exclude other contributory or causative factors
• provide expert testimony if the case goes to trial

The words autopsy, necropsy and post-mortem examination are synonymous, although post-mortem examination can also mean any examination made after death, including a simple external examination.

Autopsies are performed for two reasons: clinical interest and medico-legal purposes. A clinical autopsy is made in a hospital mortuary, after consent has been sought from and given by the relatives, and it has been used mainly for teaching and research. The medico-legal autopsy is performed on behalf of the state, and its aims are wider. It is ideally performed by a trained forensic pathologist in a mortuary with adequate facilities.

The aims of a medico-legal autopsy are to:

• determine the identity of the deceased
• determine the cause of death, the mode of dying and, wherever possible, the time since death
• demonstrate all the external and internal abnormalities, malformations and diseases
• describe in detail all the external and internal injuries
• obtain samples of tissues and body fluids for examination or analysis wherever necessary
• in a newborn infant, determine whether the child was born alive and whether it is viable

All findings are documented in writing. Diagrams and drawings are signed and dated at the end of the examination, and photographs of injuries should include a scale and an anatomical reference point. Photographs are essential in suspicious deaths.

The external examination records the age, race, sex, body length and body weight of the deceased, the skin colour and hypostasis (post-mortem lividity), personal hygiene, congenital deformities, external marks that help identification, the hands, any fluid from the orifices, and rigor mortis. All injuries are described as part of the external examination.

The internal examination follows a set sequence: incising the body, inspecting the organs, examining the body cavities, and checking for pathology. Samples are taken for toxicology and histology. The last steps are putting organs back, padding and suturing the body.

An autopsy cannot always explain a death. Some functional causes of death, such as a fall in blood pressure, a cardiac arrhythmia, spasm of the glottis or vagal inhibition, leave no trace at autopsy. The pathologist must therefore rely in part on what is reported about the events leading up to the death. Without an internal examination it can be impossible to be certain of the cause and the mechanism of death, and at least one third of the causes of death given by doctors have been shown to be incorrect when a later autopsy was made.

An expert report sets out a doctor's findings, and where relevant the doctor's opinion, for a court, a prosecutor or an investigating authority. The sub-notes below cover the kinds of report, who asks for them, how they are structured, the duties of the expert and the use of the report in court.

Expert reports are classified by their subject: reports on living persons, reports on the dead, and reports on written data. Reports on written data are based on documents and records rather than on a physical examination.

A report may be requested by the police, prosecutors, coroners, judges, medical administrators, government departments, city authorities or lawyers of any kind. Before agreeing to write one, the doctor must ask two questions: whether he or she has the expertise to write it, and whether he or she has the authority to do so.

Medical records of a living patient should be reviewed only with written permission from the patient, or from a person or body with the power to give it. Consent to disclose the effects of an alleged assault does not extend to all the medical details of the victim, so the report is limited to the relevant details. If no consent was obtained, the report must say so, and state the basis on which it was written.

Many courts and tribunals have a set format for reports. When no format is specified, a statement of facts found at examination usually contains the following, in this order:

• the legal heading, and the doctor's professional address and qualifications
• the date of the report
• the date, time and place of each examination, and the names of anyone else present
• who requested the report, and when
• the doctor's role at the time, for example having been called by the police to examine an alleged victim of assault
• confirmation that the patient consented to the release of the medical information, or that consent was sought
• the history that the doctor was given, referred to the contemporaneous notes and attributed to the person who gave it
• a simple summary of the medical findings
• any other material used as a basis for the report, such as medical records or X-rays

The report should be structured, detailed but not over-elaborate, accurate, and written so that an intelligent person without medical training can understand it. Medical abbreviations are used with care, and technical terms are explained in simple language. A court needs every relevant detail, but no irrelevant ones.

In a criminal case, a statement is a report prepared in a particular form so that it can be used as evidence. It begins with a declaration that the author must tell the truth and must not include anything he or she knows to be false. A false statement makes the author liable to criminal prosecution. A statement made as a professional witness is based on the contemporaneous notes, and it must fairly reflect what was seen or done at the time.

A statement may be accepted by both the defence and the prosecution, which removes the need to attend court. If the defence does not accept the findings, the doctor is called to give live evidence and is examined, cross-examined and re-examined.

In civil proceedings a sworn statement, called an affidavit, is made before a lawyer who administers the oath at the time of signing. In many countries a written statement or affidavit is usually enough, and personal appearance in court is unusual. In systems influenced by the Anglo-Saxon tradition, personal appearance is common, and it is the spoken evidence, tested by the defence, that carries weight.

An expert witness gives an opinion about medical facts. The duty of an expert is to the court, not to the person who asked for the report or who pays for it. The opinion must be impartial and must not be influenced by the demands of the litigation. The principles that apply in England and Wales, and that apply in many other systems, are these:

• the expert provides independent assistance to the court by objective, unbiased opinion on matters within his or her expertise
• the expert never assumes the role of an advocate
• the expert states the facts or assumptions on which the opinion is based, and does not omit material facts that could weaken it
• the expert makes clear when a question falls outside his or her expertise
• where the conclusions rest on inadequate information, the expert says so and gives the opinion as provisional
• where the report cannot state the whole truth without qualification, the qualification is stated in the report
• the expert is ready to reconsider and, if necessary, change the opinion when new information is received, and communicates a change of view without delay
• photographs, plans, calculations, analyses and measurements that support the report are provided to the other party

A medico-legal report is prepared with great care, because it either is the medical evidence on that aspect of the case or is the basis of any oral evidence the doctor later gives. A doctor who cannot sustain the facts or opinions of the report while giving live evidence may be embarrassed, unless there is a stated reason for a change. Before signing, the author should check the report for factual errors, such as the wrong site of an injury.

If new facts or hypotheses are put to the doctor in court, the doctor should reconsider the medical evidence in their light, and may accept that the conclusions are different on the new basis.

In court the witness is first questioned by the lawyer who called them, in an examination-in-chief. The other side then cross-examines, testing the parts of the evidence that damage its case, and the original lawyer may re-examine to clarify points raised in cross-examination, but may not introduce new topics. The witness is under oath throughout, and is liable to the penalties of perjury if the oath is broken.