Forensics Final

Three ways to improve observation skills include:

1. Carefully and systematically examine the area which is under investigation. .2. Consider everything that is being investigated and do not filter anything out no matter how big or small a piece or detail is. 3. Document any information (writing down and photographing information which can be used for evidence) instead of relying on memories. Since memories can be faulty, verbal testimony may be inaccurate when recalling facts regarding the crime scene.

Two ways your brain can alter sensory information

1. We are unable to pay attention to everything that is happening at one time. The brain will choose which information to take in and which to filter out in our surroundings. 2. The brain may also alter our perception. This includes filling in gaps when something is missing from a situation (for example if a word is missing from a sentence and we fill in the blank using our own predictions) or using previous knowledge to make sense of new situation (for example, if a new candy is blue we might associate it with having a blueberry flavor even before we taste it).

To determine one's blood type, what is added to the slide? a) blood and antibodies b) only the antibodies c) luminol d) none of the above

A. blood and antibodies

Blood proteins that determine blood types are a) on the surface of the cell membrane b) inside of the cytoplasm c) both on the cell membrane and inside of the cytoplasm d) found in the bone marrow

A. on the surface of the cell membrane

If a person has type A- blood, then they have a) only the A protein b) both the A and the Rh proteins c) all three blood proteins d) It is impossible to tell what proteins they have

A. only the A protein The A in A- signifies that the A protein is present, and the (-) in A- suggests that the Rh protein is absent.

Distinguish between circumstantial evidence and direct evidence, and provide an example of each type.

Circumstantial evidence is indirect evidence which does not show direct proof of a fact, but implies its existence. An example is finding the suspect's weapon at the site where the victim was injured or murdered. This provides circumstantial evidence that the suspect was present at the site where the crime occurred. Direct evidence is evidence which supports the facts directly without having to imply its existence. These will include firsthand eyewitness accounts or footage from security tapes. If an eyewitness sees the suspect attack the victim or if there is video footage of a suspect robbing the store, then these would be considered direct evidence.

DNA restriction enzymes a) are used to repair DNA b) are involved in DNA synthesis c) prevent DNA from being amplified d) cut DNA into fragments of different lengths

D. cut DNA into fragments of different lengths

Half the bands in a baby boy's DNA fingerprint are from his a) uncle b) cousin c) sister d) father

D. father Offspring receive half of their DNA from their mother and the other half from their father.

1.Blood types are determined by the presence of protein located on a) all of the blood cells b) only the white blood cells c) only on the T-helper cells d) only on the red blood cells

D. only on the red blood cells

If a person has type O+ blood, then they have a) the A and the B protein, but lack the Rh protein b) an O protein but not the Rh protein c) none of the ABO nor the Rh proteins d) the Rh protein but not the A or the B proteins

D. the Rh protein but not the A or the B proteins If a person has type O blood, his blood cells lack both A and B proteins; there is no such thing as a type O blood protein. The (+) in O+ signifies that the Rh protein is present.

Experts from different sciences agree that the definition of death is the end of life.

False Some scientists believe death is the cessation of life or blood circulation, while others believe death is the cessation of brain activity.

The Body Farm is a fictional account of the work of a country coroner.

False The Body Farm is a place where forensic experts study how environmental conditions affect the rate and succession of insect development on corpses.

The only two manners of death are natural death and homicidal death.

False There are five different manners of death: natural death, accidental death, suicidal death, homicidal death, and undetermined.

The presence of drugs in a corpse cannot be determined by a chemical analysis of larvae found feeding on the body.

False When maggots feed on a dead body, they consume whatever toxins or drugs are present in the body. These toxins or drugs become incorporated into the maggots' tissues.

Millions of individuals have identical DNA profiles.

False Every person has a unique DNA profile. Only identical twins share the same DNA profile.

Mitochondrial DNA is inherited from the father.

False Mitochondrial DNA is inherited solely from the mother.

The Innocence Project is an organization that seeks to get convicted killers out of prison.

False. It was created to reexamine cases in which individuals were convicted of a crime and imprisoned and utilize DNA evidence to make a determination whether an individual is guilty or innocent. This Project was able to identify that faulty eyewitness testimony led to many wrongful convictions.

If we remember seeing something happen, we can trust that it happened just as we think it did.

False. Memories can be faulty, so it is important to document information as it happens. That way, we can refer back to it when using the information as evidence in court.

Good observation skills come naturally to investigators; they do not need to be trained.

False. We are not naturally attuned to pay attention to the specific details in the environments and surroundings. Investigators and others need to make a conscious effort to examine the fine details of the environment in an organized and systematic way.

Blood type is considered to be class evidence. Although it may not specifically identify the suspect, explain how it still could be useful in helping to investigate a crime.

Recall that class evidence will specify the identity to a certain group of individuals or things.If the victim defends himself/herself from an attacker using an object and the object draws blood from the attacker, the investigators can narrow down the suspect from the blood type identified on that object.

In the first 12 hours, a dead body cools about 1 degree F per hour.

True

Most wrongful convictions seem to be the result of faulty eyewitness testimony.

True

The two main purposes for analyzing VNTR data from DNA fingerprints are matching tissues and inheritance.

True

The word forensics refers to the application of scientific knowledge to legal questions.

True

Within minutes of a death, certain insects are attracted by the smell of the first stages of decomposition.

True

mechanism of death describes what has occurred in the body to cause death.

True Common mechanisms of death include loss of blood, pulmonary arrest, sepsis, and hemorrhage.

In gel electrophoresis, the shortest DNA fragments travel greater distances than the longest DNA fragments

True DNA fragments are negatively charged, and the electric current created in the gel electrophoresis chamber causes the fragments to migrate toward the positively-charged end of the gel. The smaller DNA fragments travel faster and farther because they move more easily through the gel. To better understand this concept, imagine that a small DNA fragment is a small metal object, a large DNA fragment is a large metal object, and the positively-charged end of the gel is a magnet. If you hold a magnet above a small metal object, it'll probably lift the object up and cause it to stick to the magnet. If you hold a magnet above a large metal object, it might cause the object to vibrate or move around a bit, but it probably won't lift the heavy object up or cause it to stick.

Many factors affect rigor mortis, such as the type of clothing the person was wearing.

True Heavy clothing can trap heat and speed up rigor mortis. Other factors affecting rigor mortis include temperature in the surrounding environment, a person's weight, and sun exposure.

Livor mortis refers to the color of a dead body.

True When a person dies, gravity forces blood into the lower regions of the body. Then, the hemoglobin in red blood cells begins to break down and turns purple when it empties from the cells. This purplish color is seen where blood pools in the body.

Blowflies are one of the first insects to arrive at a dead body and are very useful in determining the time of death.

True the gases produced by decomposing bodies attract blowflies.

The technique used to amplify DNA is polymerase chain reaction (PCR).

True PCR allows forensic scientists to take a small amount of DNA and produce billions of copies of it in a short period of time.

Explain the difference between using DNA profiles to determine paternity and to match a tissue sample with a suspect.

When determining paternity, half of the offspring's DNA profile should match the father's DNA profile because offspring inherit half their DNA from each parent. When matching a tissue sample with a suspect, the DNA profile of each sample must be identical in order for the match to be successful. Remember, DNA evidence is unique and capable of identifying a specific individual.

A forensic scientist is called to a court of law to provide a) fact c) judgement b) opinion d) reflection

a. factb. relaxed

Transfer evidence can include all of the following except a) the victim's own blood gushing from a wound b) hair that was transferred to a hairbrush c) the blood of the victim found on a suspect

a. the victim's own blood gushing from a wound

Locard's exchange principle implies all of the following except a) Fibers can be transferred from one person to another. b) Blood spatter can be used to identify blood type. c) Cat hair can be transferred to your pants. d) Soil samples can be carried from the yard into your home.

b. Blood spatter can be used to identify blood type.

The forensic scientist has many duties. Which of these is not a job for a forensic scientist? a) give evidence in court b) question a suspect c) sign a Cause of Death document d) search for evidence

b. question a suspect Forensic scientists just examine and evaluate evidence to provide facts for a case. They do not get involved with determining if a suspect is guilty or innocent.

Our state of mind affects how we observe our surroundings. What mental state is the best for observing? a) happy c) nervous b) relaxed d) excited

b. relaxed

The Innocence Project found that most faulty convictions were based on a) out-of-date investigating equipment b) poor DNA sampling c) inaccurate eyewitness accounts d) officers not thoroughly observing a crime scene

c. inaccurate eyewitness accounts

The reason it is important to separate the witnesses at the crime scene is to a) prevent contamination of the evidence b) prevent fighting among the witnesses c) prevent the witnesses from talking to each other d) protect them from the perpetrator

c. prevent the witnesses from talking to each other

All of the following are ways to improve our observational skills except a) be sure to look at the entire area, not just the body, weapons, or signs of break-in b) observe everything no matter how big or small c) when collecting evidence, record only those things that you are sure are important d) write down and photograph everything you find

c. when collecting evidence, record only those things that you are sure are important

Correct collection of evidence requires which of the following? a) documenting the location where the evidence was found b) correct packaging of evidence c) maintaining proper chain of custody d) all of the above

d. All of the above

A crime-scene sketch should include all of the following except a) a scale of distance b) date and location of the crime scene c) a north heading on the diagram d) the type of search pattern used to collect the evidence

d. the type of search pattern used to collect the evidence