The emergency department can become a chaotic environment at times, especially when managing multiple trauma patients. But even when working at a hurried pace or when short-staffed, it is important to be mindful of evidence preservation. The first step in preserving evidence is identifying the nature (e.g., physical, sexual, emotional) and origin (e.g., accident, neglect, violence, torture, drug-related) of the injuries to determine the type of forensic evidence that may be obtained from a variety of search locations. The time from the assault should be ascertained, as evidence can deteriorate with time to the point of uselessness. For example, DNA in saliva deteriorates especially rapidly, often in less than 48 hours. It is recommended that a sexual assault forensic exam be administered within 120 hours of an attack for the collection of trace evidence; however, bruises, bite marks, and other injuries should still be documented after this time frame [8,9]. Forensic patients (especially sexual assault patients) must be encouraged at every contact to rush to an evidence collection facility [9].

Information gathered from transport personnel or during an interview regarding the type of attack can help to identify areas requiring particular detail, but this should not distract from conducting a thorough exam. An important component of the physical examination/interview is the patient's general appearance and demeanor upon presentation [8,9]. This should be recorded as objectively and with as much description as possible in a few sentences. The ability of the patient to remember details of the incident and to cooperate with the exam should be noted [8,9]. Those seeking information about the assault should work collaboratively to create an information-gathering process that is as respectful to patients as possible and minimizes repetition of questions. However, one should consider the implications of the evolving law on hearsay exceptions when determining the level and nature of coordination. In the interest of providing culturally responsive care, the patient should receive information about the procedures used during the exam before the examination begins and in a language the patient understands [8,9]. Nurses should be aware of cultural issues pertaining to specific populations and strive to respect and accommodate the needs of the patient. These include having a friend or relative present during the exam, gender preferences of medical/forensic personnel, and addressing the patient's physical comfort and safety.

Questions pertaining to the medical-forensic exam include the last six on this list, as these can help to focus the search. If ejaculation took place, this location should be identified; however, other fluids, such as blood and saliva, are also useful for DNA collection. If more than one individual was involved in the attack, the patient should identify which perpetrator committed which act(s). The account should include all violence performed and/or threatened and should conclude by asking if there were any other acts performed that were not already covered.

Forensic documentation includes a written component, a diagrammatic component, and a photographic component. Each should accurately inform the other. The written component must be detailed, accurate, and objective; the diagrammatic component must be thorough and legible; and the photographic component must include a measurement scale, be representative of the evidence, and remain objective.

In many cases of abuse and assault, the body is the only "crime scene." It is the duty of the medical-forensic examiner to accurately and diligently record the details of the injuries and the evidence present on the victim and/or perpetrator. The somewhat special skills once required by a forensic photographer shooting with a roll-film camera have been superseded by the widespread use of digital photography. Digital documentation simplifies many aspects of forensics, including ease of use, the number of images that can be recorded at very low cost, ability to review images and reshoot if needed, better control of the evidence chain of custody, and later ease of distribution during legal proceedings. Although useful as evidence, photography is not required to provide care, and patient consent should be obtained [9].

Photo documentation will typically proceed along with the physical examination and the collection of evidence. When an injury or other evidence (e.g., fluids, fibers) is found, it should be photographed. It is considered good practice to capture four images of each finding [9]. One should be an overall shot of the body and should include a clear anatomical reference (e.g., arm, hand, leg, foot), another should be a medium shot, and there should be two detailed shots of the finding. The wide and medium shots can be used to document multiple findings. Detailed shots of each finding should be taken before evidence collection, during manipulation, and after the evidence is swabbed or removed. If a lifesaving measure may disturb evidence, it is ideal to photograph the site/finding beforehand, if possible.

Bullets (or bullet fragments) are a vital piece of evidence in cases of gun violence. It is recommended that when these are removed from victims, they should be extracted with plastic-shielded forceps and handled as little as possible [1]. After they are removed, they should be immediately wrapped in gauze, placed in an evidence envelope, and the envelope marked with contents, name of person who extracted bullet, date and time of extraction, and name of the patient. Additionally, when documenting gunshot wounds, healthcare professionals should not attempt to identify entrance or exit wounds unless recording the patient's statement [1]. The caliber of the bullet should also not be guessed, as this can create a disagreement between the medical-forensic report and the law enforcement report.

The nurse examiner should then move to the oral cavity and carefully observe every surface for injury from forced entry, a hand or gag over the mouth, or other insult. Two swabs each are usually taken from the tongue, the tonsillar fossae, behind the buccal sulci, and behind the upper incisors when indicated by forcible oral copulation (or its attempt) or uncertain patient history (e.g., if the patient was drugged or unconscious) [7,8,9].

During the exam, crusted secretions or other attached material should be clipped out of the pubic hair and placed into evidence. Approximately 20 to 30 samples of the patient's own pubic hair should be plucked and kept separate as a control. A Wood's lamp should be used in the collection of semen samples from the external genital area, and again, enough swabs should be used to completely remove all visible traces. Following collection, a magnification device should be employed to further examine the area for microtrauma. A gynecologic colposcope is recommended for its sufficient lighting, magnification, and photographic capability [7,8,9]. The labia minora, posterior fourchette, and fossa navicularis typically sustain the most injury during an assault involving penile penetration only, while assaults involving digital penetration cause damage to the aforementioned sites and the vaginal walls, the cervix, and perineum (due to fingernails).

Bite marks are a feature in many types of crimes, including assaults, homicides, and child abuse. They are typically found on the arms, breasts, and neck in cases of sexual assault; on the arms, legs, and breasts in cases of homicide; and over many body surfaces in child abuse cases [8,9]. Although the science behind bite mark analysis (for perpetrator identification) is dubious, the presence of bite marks is particularly useful for guiding saliva collection, which can be used to both tie the victim to the suspect (self-defense biting) and the suspect to the victim (attack biting) [6]. Therefore, bite injuries should be given special attention and, whenever possible, should be examined by a forensic odontologist.