Zero: "Now this is a very interesting piece of evidence." Marlow: "What is it?" Zero: "It's a love letter... or rather a hate letter, depending on which paragraph you're reading. Whoever wrote this was certainly in love with the victim. Here, read it for yourselves." Wilson: "... Hum... from what I can gather of this, the guy was cheating on her, and she was mighty furious about it. Here, take a look at it Marlow.
Well I don't know about you, but if she meant half the things she wrote in this letter, we have a seriously jealous woman here. This could be a factor in our investigation, a motive; we could be dealing with a crime of passion here." Zero: "Well it could explain the struggle, but she would have to be very strong to do this." Wilson: "Or very angry." Marlow: "I don't know Wilson, I'm not convinced about this. There are just too many pieces missing here. Let's just send this letter to the lab and see if they can tell us anything."
Documents found at a crime scene are collected by the Forensic Identification Unit. They are placed in cellophane or plastic envelopes, and are never marked, defaced, altered, or folded. At the lab, they analyze the paper, ink, and handwriting. Paper and inks, and handwriting analysis are forensic science disciplines under the umbrella "Questioned Documents". Writing instruments, typewriting, photocopying, computer printers, computer disks, forgery, gambling machinery, rubber stamps, and the dating of documents are also disciplines under Questioned Documents. The concepts of class and individual characteristics are applied to mechanically produced documents for the purposes of identifying the equipment used. Handwriting analysis examines the design, shape, and structure of the handwriting to determine authorship. Graphology is not a forensic science but rather, the study of a person's handwriting to determine their personality traits.
- Fingerprint anaylsis
|
Clue # 3 : Fingerprint AnalysisLab test :
One of the prints came up with a positive match in our database. They belong to a certain Patrick Murray, A.K.A. "Pat the Rat". He's been convicted twice for break and enter, and theft, and was arrested once for assault, but wasn't convicted for that. His parole officer says he's now working for an electrical company called "Bright Lights "R" Us"."
However, prints on vase that killed victim belonged to someone else with no criminal record |
Marlow: "Have you found any prints?" Zero: "Yes, as a matter of fact we found about thirty different sets of fingerprints when we dusted this place." Wilson: "Wow, this was a popular guy!" Zero: "I think you guys should know that one of the prints we lifted was from a crystal vase that was used to hit the victim across the jaw during the struggle. We found traces of his blood on the vase, and the bruises on his face are consistent with the shape and weight of the object. The blow must have stunned him, but it didn't kill him; the knife is what killed him." Wilson: "So you're saying that the prints from the vase might be the killer's?" Zero: "Or the killer wore gloves and those prints are from someone who just happened to touch that vase, God knows there have been enough people in this house! Anyway, all this deduction is your job, I just collect the evidence.
I sent the fingerprints to the lab for analysis, but a few of them were too smudged for a decent comparison."
Fingerprints are gathered at the crime scene by the Forensic Identification Unit. Proper precautions are taken not to damage or destroy fingerprints or add fingerprints to evidence. At the lab, digital technology is used, called the Automated Fingerprint Identification System (AFIS).
Different surfaces require different techniques for developing fingerprints. The technique most commonly known is powder processing. This is where powder is brushed over a print and minute particles of powder cling to the print residue. The print is then lifted with a piece of tape. With the advancement of forensic science, there are now special processes that develop prints on paper, wood, cardboard, skin, and objects that have been in water.
Clue # 4 : Fiber Analysis lab test - made of 50% wool and 50% polyester. They are dyed black and the weaving is very common for sweaters and such things."
Wilson: "So what else do you have for us in this room, Zero?" Zero: "Well, over here we found fibers caught on a fragment of that broken chair. It must have occurred during the struggle. I guess Locard was right." Marlow: "I beg your pardon?" Zero: "You know, "Locard's Exchange Principle": when someone comes in contact with another person or place, something of that person is left behind, and something is taken away. Anyway, I'm sending these fibers to the lab, Doc will be able to tell you a lot more than I can."
Fibres found at a crime scene are collected by the Forensic Identification Unit by their fingers or tweezers. They are then placed in paper which is then sealed and marked. At the lab, they use either a compound microscope or a comparison microscope. Fibre analysis utilizes the concepts of class and individual characteristics, thereby determining the type and colour of the fibre. In some cases, the expert can even determine the particular garment or fabric. The search for fibres at a crime scene is done because of a principle called "Locard's Exchange Principle": when someone comes in contact with another person or place, something of that person is left behind, and something is taken away.
Place of murder
Clue # 1 : Bloodstain Pattern Analysis |
Wilson: "It looks like the poor guy put up quite a fight..." Coroner: "Yes, as you can see from the splatters of blood on the wall it was a pretty messy death. Not that there's ever anything not messy about death." Marlow: "So what happened?" Coroner: "Well, as you can see on the body, there are two puncture wounds, one to the neck, and the other to the heart. Now, those splatters on the wall occurred when the suspect stabbed the victim in the neck; he hit the carotid artery, you see, causing the blood to come out in spurts. When you hit a major artery like that, a great loss of blood occurs within only a few seconds." Wilson: "Meaning?" Coroner: "Meaning that the victim lost consciousness very quickly, so there was no way he could defend himself against the second attack when the suspect aimed for the heart. He fell where he stood, and died almost instantly. Now, the large bloodstain that seeped under the body mostly came from the wound to the neck. The wound to the heart bled a little and that's only because the suspect pulled out the knife from the heart of the victim -and as you probably noticed the murder weapon is nowhere to be seen. You see, if he had left it in, there would be almost no blood from that wound, the knife would have acted as a sort of plug.
They'll probably give you more details at the lab."
Lab test: Doc: "Well, I've studied the photos of the blood spatters and blood stain and it's pretty straightforward stuff. The spatters are from the wound to the carotid artery in the neck and..." Wilson: "Yes, the Coroner told us all that. Can you tell us anything about the suspect based on these stains." Doc: "Well, judging from the pattern of the spatters on the wall from the neck wound, the attacker lunged forward at the victim using a downward motion. Now in order to that he must be at least as tall as the victim." Marlow: "So the suspect is approximately 5'9" tall." Doc: "I can also tell you that whoever did this knows what he's doing. Stabbing at the carotid artery and the heart like that ... the suspect has been in many fights ..." Wilson: "So the suspect was deliberately aiming in those spots to kill. It was premeditated then." Doc: "No, not necessarily premeditated. The suspect could have been taken by surprise and reacted violently. But his -or her- instincts to go for those two areas of the body shows experience in fighting for one's life; like a criminal would in prison or on the streets." Marlow: "Or anyone with extensive self-defence training. Thanks Doc."
Blood Stain Pattern Analysis Blood stain pattern information is gathered at the crime scene by the Forensic Identification Unit. They take notes, sketch, photograph, and video tape the patterns. They are then examined by a technician at a forensics laboratory. Blood reacts, as all liquids do, in a predictable, consistent, reproducible manner. The types of reactions are called 'standards'. These standards can tell the expert how a crime was committed by the stain the blood leaves. Different splatters occur, for example, when blood falls from different heights. When there is a blunt force trauma, and blood splatters, the stains left are called 'cast off stains'. These cast off stains reveal the direction and number of blows, the size of the object used, the orientation of the person, and if they are right or left handed. |
|
| Clue # 2 : Blood Analysis |
Marlow: "What about blood types, is all this blood the victim's or did you find traces of the suspect's as well? I mean, it seems to me that with such a nasty fight, the suspect must have gotten a few scratches at the very least." Coroner: "Unfortunately, we only found one blood type in this area, and it's the victim's. There was no skin or blood under the victim's fingernails, suggesting that he didn't scratch his attacker. However, we did find traces of blood that are not the victim's, in the bathroom, next to the sink." Wilson: "So are you saying that the suspect did get hurt somehow, and washed up before leaving the crime scene?" Coroner: "It's possible...but not very probable. That blood could belong to someone who has nothing to do with this murder; it could have been there for weeks ... anyway, I sent the samples to the lab, they'll be able to tell you more."
Lab test : -> only two, one of which belongs to the victim. Now the other sample, the one they found next to the bathroom shows, through DNA testing, that whoever this blood belongs to is a woman."
Blood Analysis (from simple blood type to DNA) Blood samples at the crime scene are collected by the Forensic Identification Unit. They are picked up by a gauze pad or other clean sterile cotton cloth, rolled in paper or placed in a brown paper bag or box, which are then sealed and labelled. Plastic containers are not used. The blood is then analyzed at a forensics lab by a technician.
Blood found at a crime scene can tell through chemical analysis if the person has any drugs or poisons in his or her system. Through DNA analysis a person's genetic make up may be identified. A very important use of DNA typing is the identification of perpetrators of a crime by comparison of biological samples of suspects against biological specimens that the perpetrator of a crime has directly left at the crime scene (e.g. semen, saliva, skin, or blood). The reason blood can tell the forensic specialist what race a person belongs to, for example, is because all people within a particular race have a similar DNA code sequence, as everyone who has brown hair has a similar code sequence for brown hair. The coding sequences, however, are separated by 'junk' DNA. This 'junk' DNA is non-coding and separates coding sequences. The 'junk' DNA sequences are random and unique to each person. This is why blood samples can identify or eliminate a suspect.
|
Clue # 3 : Wound Analysis |
Marlow: "What else can you tell us about the body?" Coroner: "Well, there are two puncture wounds. One to the neck and the other to the heart. Both were made with the same weapon, probably a switchblade. Unfortunately, we haven't found the murder weapon yet; and if you ask me, I don't think we ever will. Anyway, the Forensic Identification Team has taken quite a lot of photographs of the wounds and I've just sent them to the lab, so if you want more detail you'll have to ask the forensic pathologist over there."
Lab test: two clean puncture wounds ... yes, he was stabbed twice, once in the neck and once in the heart. Now, the nature of the wounds indicate that the blade was narrow and approximately four inches in length. Also, it must have been a good quality blade as it didn't break when the attacker stabbed the victim in the heart." not easy to stab someone directly in the heart. You see, you have to get past the thoracic cage, which, as its name indicates is designed to protect the vital organs including the heart. So, since the blade went all the way through, and its tip didn't even break when it nicked the ribs, it was a good quality switch blade."
Wound Analysis (created by a small pocket-knife) Wounds on a victim are looked at by the Forensic Identification Unit and photographed. At the lab, they are further analyzed by a forensic pathologist. Wounds are analyzed using the concepts of class and individual characteristics. For example, an incised wound is the cutting injury caused by the slicing action of a blade-like object. The edges are smooth, but this could be from a serrated or smooth blade. A puncture made by a sharp object would be a different class of wound. |
| Clue # 4 : Time of Death |
Wilson: "Do you think you can tell us at what time the victim died?" Coroner: "Oh yes, no problem. First of all, if we consider livor mortis, that is the setting of blood in the dependant regions of the body following death, we can see that all the blood has accumulated in the back of his body. This suggests that, after he died, he was lying on his back for several hours -it also shows that he was not moved after he was killed.
Now, if you are looking at rigor mortis, which is the chemical reaction that causes rigidity in the muscle groups following death, that suggests that he's been dead for over twelve hours. You see, what happens is that after about a half hour the muscles go stiff; but then they go limp again. It's only after about twelve hours that the body becomes very stiff, and this guy is as stiff as a board. Also, if you consider algor mortis, which is the cooling of the body, again I would say that he's been dead for over twelve hours. Now, taking all that into consideration, I would say that the victim was killed at approximately 10:30 PM last night. An autopsy should confirm this." Wilson: "Thanks."
Lab test : about 10:30 PM on the night before the body was found."
Pathology (time of death) The time of a victim's death at a crime scene is estimated by a forensic pathologist. Further information about the victim is gathered when the autopsy is done at the lab. The pathologist determines how and why the victim died, and whether it is a homicide, suicide, accidental death, or death by natural causes. If it is a death by trauma, they look for a laceration, incised wound, puncture, abrasion, contusion, or gunshot wound. For the time of death, the pathologist considers algor mortis, the cooling of the body; livor mortis, the setting of blood in the dependant regions following death; and rigor mortis, the chemical reaction that causes rigidity in the muscle groups immediately following death. Livor mortis can also determine whether or not the body has been moved.
Conclusion Marlow: "Well if you ask me, I think "Pat the Rat" did it.
As you just pointed out, he has a pattern of robbing the houses where he has worked as an electrician. Now granted, nothing was missing from the victim's residence, but it doesn't mean that he wasn't there that night with the intention of robbing the place. You see, what I think happened is that he went back to the house that evening knowing that the victim was going to be out -unfortunately Hughes must have let that slip in front of him earlier that day.
So he goes back, checks the place out -if you remember, Mrs Smith, the next door neighbor saw him lurking about at around 10:00 PM that night. Anyway, the lights are out; no one seems to be home so he goes to the back door and forces open the lock, not realizing that he had left a footprint in the mud. You remember Wilson, the footwear impression that forensics found was a men's size 11 boot. Now the reason we never found such a pair of boots in his possession is probably because he saw the footprint when he rushed out the house after the murder. He was smart enough to realize that this would implicate him and so he got rid of the boots. The shoe size, however, is consistent with his.
OK, so he's in the house now and is about to rob the place when he's caught by Hughes -the victim probably forgot something and came back for it. As you can imagine Hughes was not pleased about this and confronted Pat. A struggle ensued, leaving the mess that we saw in the living room. The fibers we found on the broken chair matches the fabric of one of Pat's sweaters, although that in itself doesn't prove anything, the fabric is so common we could match it to anyone's sweater.
Anyway, during the fight Pat picks up the crystal vase and hits the victim across the jaw; and if we didn't find his prints on the vase it's probably because he was wearing gloves like any decent thief would. The prints we did find that belonged to him were left when he was working there earlier that day.
So Hughes has been stunned by the blow he just received, he staggers to the hallway. Pat panics, he knows he's been found out, and so he takes out a switchblade to finish the job. His vast experience in prison and on the streets has taught him where to hit for instant death. Even if he didn't mean to kill Hughes, his instincts probably took over and did the job for him. With wounds like that, the victim falls to the ground, dead in no time. Pat the Rat realizes what he's done, and gets out of there as fast as his legs can take him. Being the good criminal that he is, he destroys all the evidence that could incriminate him. He gets rid of the boots, the crowbar, the clothes he was wearing, and he especially gets rid of the murder weapon. If it hadn't been for Mrs Smith, it would have been a lot harder to find him!
"Pat the rat" was the culprit!
|
|
|
