Human bites and the risk of human immunodeficiency virus transmission.

The risk of human immunodeficiency virus (HIV) transmission following a bite injury is important to many groups of people. The first are those who are likely to be bitten as an occupational risk, such as police officers and institutional staff. Another group are represented by the victims and perpetrators of crimes involving biting, both in attack and defense situations. The possibility of these bites transmitting a potentially fatal disease is of interest to the physicians who treat such patients and the legal system which may have to deal with the repercussions of such a transmission. Bite injuries represent 1% of all emergency department admissions in the United States, and human bites are the third most common following those of dogs and cats. The worldwide epidemic of HIV and acquired immunodeficiency syndrome (AIDS) continues, with >5 million new cases last year and affecting 1 in 100 sexually active adults. A review of the literature concerning human bites, HIV and AIDS, HIV in saliva, and case examples was performed to examine the current opinion regarding the transmission of HIV via this route. A bite from an HIV-seropositive individual that breaks the skin or is associated with a previous injury carries a risk of infection for the bitten individual.     

An assessment of human performance in stabbing.

Stab-resistant body armour is now becoming a standard item of equipment for police officers in the United Kingdom. In the UK these are usually required to have a stab resistance as specified by the Police Scientific Development Branch KR42 standard [G. Parker, PSDB Stab Resistant Body Armour Test Procedure, Police Scientific Development Branch, Publication No 10/93, 1993]. There are several other test standards, all of which specify that body armour must resist penetration by a specific blade type delivered at a specific energy level or range of levels. However, the actual range of energy levels specified varies over almost an order of magnitude and the basis for these levels is not clearly defined. This paper describes tests to determine the energy range and characteristics of stabbing actions that might be directed against stab resistant body armour by an assailant. The energy and velocity that can be achieved in stabbing actions has been determined for a number of sample populations. Volunteers were asked to stab a target using an instrumented knife that measured the axial force and acceleration during the stabbing. The maximum energy obtained in underarm stabbing actions was 64 J whilst overarm stabbing actions could produce 115 J. The loads produced on contact with the target often approached 1000 N.     

An unusual case of railway suicide

A rare case of suicide in which the victim had been lying along the railway track in a supine position and with extended extremities is described. The wheels of a train caused longitudinal hemisection with complete evisceration. Epidemiological data on train suicides are given and the relationship between this method of suicide and mental illnesses and consumption of alcohol are discussed.     

Characteristics of gunshot wounds in the skull.

The analysis of trauma to the skeleton is an important aspect of forensic case work, but most pathology references devote limited attention to this topic. This paper describes various aspects of gunshot wounds, including entrance and exit patterns, angle and path, range of fire and velocity, and caliber of the bullet, based on observations of a series of known cases. Skeletal remains of 21 victims of gunshot wounds were studied. In most cases, there was documentation of the investigation, autopsy, and victim's identity. Each case was analyzed in terms of wound location, shape, size and exit/entry surface area ratio, beveling, and direction of shooting Skull entry wounds were most often round or oval. Unusual shapes were observed in bones like the mandible and mastoid process, but were also found to be triangular, nearly rectangular or irregular. Tunneling was observed in the mastoid process. The expected internal beveling was obvious in all but one skull. External beveling of an entry wound was only observed in one case (parietal bone). Exit wounds were roughly round, oval, square, and rectangular and were always more irregular than entry wounds. External beveling of exit wounds was observed in most vault bones, but there was none in the orbit, maxilla, greater wing of the sphenoid, temporal, or left occipital bone. Tangential gunshot wounds were seen in a mastoid process, zygomatic process, mandibular ramus and condyle, and occipital condyle. Most of the exit to entry surface area ratios (cm2) varied from 1.4 to 2.0. In four cases the ratio indicated that entrances were larger than exists. In conclusion, understanding of gunshot wound characteristics is an important matter to interpret distance, velocity, direction and sometimes caliber size. Assessment of this nature of gunshot wounds helps reconstruct events surrounding the death.