1. Three
   Four
2. Eight
   Too many to count

Humans can have type A, B, AB or O blood. The blood types are further divided up by what sort of antigens the cells carry -- a subject too complex to go into here.

1. Allo-
   Hema-
2. Naturo-
   Soma-

The prefix "hema-" comes from the Greek word "haima," meaning "blood." You'll see it in names of certain tests run on blood.

1. Alphonse Bertillon
   Francis Galton
2. Sir William Herschel
   Arthur Conan Doyle

Bertillon, Herschel and Galton made contributions to anthropometry (body measuring) or fingerprinting in the 19th century. Arthur Conan Doyle was a writer who created Sherlock Holmes, the fictitious character who sometimes used early versions of forensics. However, that doesn't actually qualify as a contribution to the field!

1. 1940s
   1970s
2. 1980s
   2000s

The PCR-STR process was developed by eccentric scientist Kary Mullis. He credited LSD with helping open his mind to new ways of thinking about science. (Disclaimer: He has since become an AIDS denialist, a climate-change denialist and has reported seeing an alien in the guise of a glowing green raccoon.)

1. The cheek
   The inner ear
2. The scalp
   The wrist

The cheek is easy to access, yet protected from most forms of transfer DNA. An exception might be in the subject has recently been kissing, in which case the other person's cells might have transferred to the subject's mouth (as seen, for example, in the movie "Gattaca."

1. Ataxia
   Arthritia
2. Rigor mortis
   Stasis

"Rigor mortis" is Latin for "stiffness of death." Bodies do not remain rigid; the condition peaks about 12 hours after death and then the muscles slowly begin to relax again.

1. Their pen or pencil
   A household surface
2. The milk carton in their fridge
   Their toothbrush

Most people don't share toothbrushes, making them a good source of cellular material. The other objects named above are too readily touched or handled by other persons.

1. Hair follicles
   Skin
2. Sweat
   Urine

This is a bit of a trick question. Urine is sterile, and does not in itself contain DNA. But urine can carry skin cells from the lining of the bladder, so it's possible to get DNA from urine in that way.

1. Tire-track analysis
   Ballistics
2. Blood-spatter analysis
   IQ testing

Almost anything can be "forensic," in the dictionary definition of "detailed and minute analysis." But criminal forensic science, as we define it today, doesn't include IQ testing -- that would be done by a psychologist.

1. Autosomal DNA
   Fingerprints
2. Mitochondrial DNA
   Blood type

Fingerprints are unique, even to identical twins. But both kinds of DNA, autosomal and mitochondrial, are shared by twins. As, of course, is blood type.

1. Unfortunate
   Inconclusive
2. Invalid
   Semi-valid

A forensic scientist should never be afraid to admit a result is inconclusive. Often, a person's freedom hangs in the balance; the evidence can't be forced to fit a desired outcome.

1. Erthyemia
   Hematic migration
2. Livor mortis
   Gravity

Livor mortis presents as a bluish color in the lowest points of the body (the back, if the corpse is on its back; the front, if it's on its stomach, and so on). If a body has these patches at higher points, it indicates the body has been moved post-mortem.

1. Hidden
   Latent
2. Invisible
   Wispy

Most fingerprints at a crime scene are latent. That why technicians dust for them -- the dust makes them visible, then transferable to a surface for later analysis.

1. Warfarin
   Luminol
2. Ninhydrin
   Resolve

Luminol is a substance that reacts with the iron in hemoglobin. It glows when exposed to that iron, hence its name.

1. True
2. False

DNA testing is capable of determining family relationships, in which DNA is not identical, but has more points of similarity than that of a stranger. If this were not true, DNA testing couldn't be used to determine the father of a baby.

1. Ear prints
   Footprints
2. Palm prints
   Any of these

It's a misconception that only fingerprints have identified suspects. Given adequate imprinting on surfaces, other parts of the body can be used as well.

1. The victim's blood type
   Whether the killer was injured
2. The positions of the victim and killer
   The killer's blood type

A void area appears where an object at close range intercepts spurting blood, which can be seen on either side of the void. Often, this object is the killer's body itself. Put more bluntly, if someone slashes another person's throat, there'll be a void area on the wall behind them from where the blood spattered onto the killer's own upper body.

1. Alluvial
   Maternal
2. Mitochondrial
   X-

The significance of mitochondrial DNA is that it survives much longer than nuclear DNA (which comes from the nucleus of the cell). Mitochondrial DNA has been used in cold cases like that of Jack the Ripper (though without definitive results).

1. An sample of generous size
   A sample from a criminal suspect
2. A sample from a known source
   A sample that's been kept in controlled climate conditions

A "control sample" is like the control in a science experiment: It's the known factor. So if a person is missing, and there's blood at their home, police might take a DNA sample from a full-blood sibling as a "control sample." If the DNA from the blood at the scene is a near-match for that of the sibling, that's conclusive: It's almost certainly the missing person's blood at the scene.

1. Autopsy
   Firearms analysis
2. Handwriting analysis
   Digital forensics

Handguns and rifles have "rifling" in the barrel, a spiral pattern that makes the bullet spin, and thus keep a straighter trajectory. The rifling leaves "grooves" (scraped-away areas) on the slug; "lands" are the unmarked the metal between the grooves. This is how investigators can sometimes match up a slug to the gun that fired it.

1. Body parts
   IQ
2. Hair length
   Psychological health

Alphonse Bertillon created this system of taking about 20 body measurements to create a nearly unique profile of an offender. It became obsolete with the rise of fingerprinting.

1. Documentation of who had the evidence at every stage of the investigation
   The stages of analysis that biological evidence undergoes
2. The route a body takes to the morgue
   The shackles a suspect is kept in

After an piece of evidence -- let's say, a shell casing -- is collected at the scene, documentation is kept of who had it at every point, all the way through to trial. This decreases the chances that someone could tamper with it and not get caught.

1. The skin has acids that are uniquely identifiable.
   The skin heals in the same unique pattern.
2. If the skin doesn't heal, the damage is usually unique to also be identifiable.
   Either #2 or #3

Certainly, criminals have thought of this. It doesn't usually work. Much better to wear gloves (though that won't prevent other types of evidence, like hairs and fibers, from being left at the scene).

1. Arch
   Loop
2. Moue
   Whorl

There are three basic formations in the ridges of a fingerpint: arches, loops and whorls. A "moue" is a petulant expression made with the mouth -- you'll recognize this term if you read vintage novels.

1. Handwriting
   Explosives
2. Fingerprints
   Blood spatter

A handwriting sample is called an "exemplar." When blood or DNA is in question, the forensic scientist would ask for a "sample" or "specimen" instead.

1. Unusable
   Minute
2. Miniature
   Trace

Trace evidence can include hairs, fibers, bits of soil and more. How much trace evidence is collected at a scene depends on how thoroughly investigators can go over a scene -- which is, in turn, dictated by departmental resources. Most jurisdictions can't afford to send a battery of technicians to swarm over every crime scene.

1. Jurors
   The victim
2. A suspect
   Anyone who had recent access to the scene, including police personnel

Police officers and other investigators usually have fingerprints on file, in case they leave some at a crime scene. Likewise, other people living in a house where a crime took place might be fingerprinted. With these people ruled out, an unknown fingerprint is likely to be that of the criminal.

1. Evidence left by a homeless person
   Evidence that won't last long without protective measures
2. Evidence in a trial that is about to begin
   Evidence that is so small as to be microscopic

A fingerprint made in water-soluble paint is transient evidence at a rainy crime scene. Direct sunlight, intense heat or intense cold can also threaten the "half life" of evidence.

1. The drop in crime due to criminals fearing being caught through forensics
   The flood of students joining forensic-science programs since the advent of TV shows about it
2. The tendency of jurors to overestimate the infallibility of forensic evidence
   The drop in crime on nights when everyone is home watching "CSI"

"CSI effect" is the increasing tendency of average jurors to expect sophisticated forensics in every case, and to assume that forensic evidence is always 100 percent reliable. Defense attorneys want potential jurors to understand that cases don't hang on forensics alone -- motive still needs to be established, eyewitness testimony heard and so on.

1. Contamination
   Involvement
2. Machination
   Tampering

Contamination occurs when evidence isn't treated with proper respect -- for example, if a technician were to handle it with bare hands, getting skin cells or fingerprints on it. It's only tampering if it's deliberate.

1. Limited resources
   Human error
2. Deliberate tampering
   All of these

Jurors increasingly believe that forensic evidence is infallible. But human error or deliberate tampering with evidence can bring about the wrong result. Limited resources come into play when agencies don't have the funds or personnel to collect enough evidence at a scene. Evidence can't be analyzed if it was never brought to the lab.

1. Data known to everyone
   Data relevant to a specific criminal case
2. External or "envelope" information
   Data that does not actually exist

A date stamp or timestamp on an email is an example of metadata. Overall, metadata is information that isn't part of a message or content, but tells experts in digital forensics where a message originated, and when and who might have sent it.

1. Composition
   Decomposition
2. Deconstruction
   Gross

Everything organic decomposes, right down to leaves and grass. But the type of decomposition that interests forensic investigators -- specifically, forensic anthropologists -- is human body decomposition.

1. La Jolla, Calif.
   Knoxville, Tenn.
2. Lovelock, Nev.
   Boston, Mass.

Patricia Cornwell made this research facility famous when she wrote about it, even naming the book, "The Body Farm," after it. Actually called the University of Tennessee Anthropological Research Facility, it has more than a thousand people pre-registered to donate their bodies to the "farm."

1. Blood spatter analysis
   Fiber analysis
2. Handwriting analysis
   Video analysis

The number of blood stains, clothing fibers and handwriting samples that need examination has remained more or less steady in the last decade. But smartphones and similar technology have created an explosion of video evidence, requiring many more experts who can recover, analyze and authenticate video recordings.