The crime scene should be surveyed to exactly determine what may have happened. This is a crucial phase of crime scene investigation that involves a police officer as well as an investigator. This phase involves; making observations at the entire scene and then forming early theories regarding what may have taken place in due course of the crime. An investigator is not supposed to make any snap conclusions when they carry out this task since the hypotheses are open to change until forensic examinations are carried out (Eunice, 2009). In this sexual assault crime scene, the investigator will obtain necessary information from the two living victims.
This first hand information is very important for the investigator to gather and preserve the exact evidence. It is important for an investigator to gather as much information as he or she can so as to increase the probability of collecting the most exact evidence. For instance, if the victims tell the investigator that the sexual assault did not involve oral penetration, then the investigator will be aware that there is no need to take oral swabs. The collected information should be handed to the crime laboratory for the forensic scientists to process the evidence. It is important that evidence should only be submitted if relevant information is passed along.
According to Gilbert (2007), the victims of sexual assault should be taken to hospital as soon as possible for the examination to start immediately. The possible injuries on the victims should be photographed to document the evidence. If necessary, vaginal, anal, or oral swabs should be collected from the victims and should be air dried for a period of one hour as soon as possible by use of a fan. It is advisable that collection of evidential samples should be done as soon as possible because some constituents in seminal fluid can be broken down in the body due to enzymatic actions. The samples such as the evidential swabs are air dried so that to make the conditions unfavorable for the growth of microorganisms which can alter the evidential value of the samples.
Apart from the swabs, the panties of the victims provide the best place to collect evidence because they will trap the drained seminal fluid, and this happens especially when the sexual assault was anal or vaginal in nature. If the stains on panties are wet, the panties should be air dried. The victims’ clothes can also trap the seminal fluid in the case where assailant ejaculates on the victims’ clothes. The suspect’s hairs or blood stains can also be found on the clothes of the victims. Clothing should be packaged separately in paper bags after they have been air dried. Polythene paper bags are not used for packaging (Becker, 2008).
Another source of evidence concerning the suspect includes bed sheets, spreads, and comforters. An investigator needs to be very careful with the value of this kind of evidence it is collected. This is because the bed may have a lot of contamination from other sources, especially when it has not washed recently. Therefore the beddings should have been washed recently if valuable evidence is to be collected. The investigator should employ a technique called side lighting to ensure that even the trace evidence is collected (Becker, 2008).
The stains on the sheets should be circled and air dried before permanent packaging of the sheets. It always advisable that the sheets should air dried and packaged in separate paper bags to avoid contamination for final submission to the crime laboratory. Reference samples are collected from the suspect for thorough comparisons. The samples will constitute saliva, whole blood sample, head hairs, and pubic hairs. All the samples are taken to the crime lab for forensic investigation (Gilbert, 2007).