According to the case, there are signs of struggle in the body. If there was a struggle, it is very likely that whoever the victim struggled with would have left traces on her. The victim’s body would have to be thoroughly examined for possible traces. And for struggles, traces of skin or blood from the assaulter are usually found under the finger nails of the victim. Semen or other bodily fluids are also another possible trace the suspect could leave on his victim in the case of a rape.
It could also at least determine who the victim was recently with before she died in cases where the victim might have had consensual sex with somebody before she died. The body should also be examined for other markings that could possibly lead to the killer. If a weapon was used, it would have left marks or substances on the body that would be unique to it. Different kinds of knives or blades leave different kinds of wounds and slashes.
In some cases for example, then a killer punches his victim wearing a ring on his hand, the rings will leave an impression on the skin of the victim. These seemingly small details are what usually make the strongest link between a suspect and a victim. And if the killer could leave traces on his victim, so can the victim leave traces on her killer as well. A struggle indicates that the victim fought back. Therefore she could have scratched, wounded or injured her killer as well.
The body of suspects should therefore be examined for wounds or injuries as well. These wounds or marking would be a great help in finding out who the real killer is from a list of possible suspects. The victim can also leave traces on the weapon used to kill her (if a weapon was used). The weapon to have killed her would have made a direct contact with the victim which is why the victim will inevitably leave traces on it too. Finding the murder weapon is one of the most crucial aspects in finding out whom the killer is.
And lastly, in any crime scene, we should never forget to check for finger prints in every surface that could possibly have them; inside the car, on the black plastic bags used to wrap the victim, on the victim herself, etc. These prints, if they cannot immediately confirm the identities of not necessarily the killer, but whomever made physical contact with those objects in the crime scene, from any database, they could at least serve as small parts of the complete identity of the whole killer which would eventually be very instrumental in determining who and who is not guilt of the crime.
Moving out of the crime scene, according to the case there is a report of a woman who has been missing for a few weeks. The investigation of the background of that woman turned out that she lived an unhealthy lifestyle and was known for being a drug user and prostitute. She was also last seen alive six weeks ago. How do we now determine who the dead girl is or confirm if she is also the missing girl? The easiest way would be to check if there is any form of identification on the dead body.
Assuming there is none, the first and most direct way would be to search the room of the missing girl. There are so many things in there that could provide a DNA sample of the girl; her toothbrush, hair from her comb or hairbrush, and other things that come in contact with her body. That DNA would have to be compared first to the DNA sample from the dead body, and then from the other DNA samples that have been collected in the field. Once that has been verified, we can then proceed to understanding more of the case.
Since the missing girl is a drug user, her dead body (assuming that it is her) should also be checked for drug substances to determine if she took some drugs before she died. She could have died from overdose for that matter and whoever she was with just buried her out of fear of getting caught using drugs instead of calling 911. The investigators now have a new angle to try and understand – what is the connection of drugs to her death.