Forensics

Question 1

Three types of modes of death

Answer 1

• natural
• unnatural (accidental, suicidal, homicidal)
• unknown

Question 2

What deaths are reportable to the coroner or ME

Answer 2

• unexpected
• suicide
• accidental
• while in custody
• self-abortion
• etoh intoxication
• Not: dies under provider’s care, knew sick, know likely to die

Question 3

Rigor Mortis and body temps

Answer 3

• occurs at 3 hours
• 4 hours: extremities still warm
• 6 hours: trunks still warm
• Lose about 1.5 degree body temp F per hour dead

Question 4

Dependent lividity

Answer 4

• Occurs where blood pools after heart stops beating
• Red where blood pools, white where body was bearing weight
• Allows understanding of body position after death
• Also, if see during resuscitation, sign person will not recover…

Question 5

What animal eats in a linear, buffet fashion?

Answer 5

rats

Question 6

What to think when see abrasion, damage to neck on dead person?

Answer 6

• could be pre-death injury
• Could also be a post-mortem finding, skin becomes very fragile and tears easily, could be due to rough handling by EMS, funeral home, etc.

Question 7

How does tension pneumo kill?

Answer 7

Pushes mediastinum away from injured side, can squish vena cava, kinks it like a hose = no blood to heart. Tx will quickly resolve!

Question 8

What to consider if pt has road rash

Answer 8

If not removed in 24 hours becomes a perm tattoo

Question 9

Signs of basilar skull fx

Answer 9

• battle sign (behind ear)
• raccoon eyes
• CSF otorrhea and CSF rhinorrhea
• TM perf
• Hemotympanum

Question 10

What is a pattern contusion

Answer 10

bruise that shows what was used to cause injury: pool stick injury

Question 11

How to differentiate injury dt fall vs. fight?

Answer 11

• Fall injuries will occur on the “parts that stick out” on the face
• Fight can occur in recessed areas like eye socket.

Question 12

Laceration definition and how to differentiate from cut

Answer 12

• blunt trauma
• skin stretches until it rips in a jagged fashion
• will contain bridging tissue (area that survived trauma)
• will contain abrasion around the wound
• Cuts will be straight, no surrounding abrasion

Question 13

Child abuse

Answer 13

• bruising on face, abdomen, thighs, hips
• Lacerations on lips (scalloped edge if not repaired)
• Flagellation marks from whipping
• Cigarette burns: round
• Cephalohematoma: grab by hair and pull

excuse me while I vomit

Question 14

MVA

Answer 14

• Extent of accident does not always equal extent of bodily injury
• Ask: where in car, seat belt worn? Will help determine MOI
• Chevron marks: tire ran them over

Question 15

Auto-Pedestrian accidents

Answer 15

• can sometimes tell how person was standing when hit:
• bilateral injury at same level indicates standing still
• bilateral injuries at different levels indicates moving
• Check wounds for paint fragments
• Look at the car

Question 16

IV drug use tid-bits

Answer 16

• Smoke, soot, etc. on needle is cause of peri-venous fibrosis (hypo pigmentation)
• Bent needle = easier access
• Bulb syringe: use to get all drug by washing out
• Skin popping: SQ injection vs. IV. Lesion called “rosette”. Can get infected and ulcerate
• Frothy edema
• Tattoos: Charlie Chaplin/King Herald = heroin, can be used to hide tracks, roadmap to veins

Question 17

Hangings

Answer 17

• leave a looped mark, not a straight line
• If hang long enough will get petechia in leg called tardieu sign, turn into purpura
• Don’t forget about autoerotica… Family might try to cover it up

Question 18

Signs of smothered with a pillow

Answer 18

White around lips, nose, chin

Question 19

Knife injuries

Answer 19

• Dull: black collar abrasions (dt friction)
• Single edged: sharp on one side of the cut, dull on the other
• Figure 8 and dull: scissors
• Hands: usually sign of defense
• Prod marks: poke marks near injury
• Vital erythema (cut when alive, red and blood) vs. no blood (cut when dead and not bleeding)

Question 20

What should you try to do when cutting off clothing and treating patient

Answer 20

• try to not damage evidence (cut through GSW hole)

- look for evidence like paint, keep if you can

Question 21

GSW

- how to tell if from distance or close

Answer 21

• close will have soot, gunpowder, etc. on skin

- Far will just be damage from bullet

Question 22

GSW

- enter vs. exit

Answer 22

Entrance hole 
- will be smaller than bullet (stretches skin as enters)
- Collar abrasion
- Bone spicules travel same direction as bullet
Exit
- bigger hole bc now bullet tumbling
- no soot, etc. 
- stellate dt tumble

*** NEVER name entrance or exit, just number wounds 1, 2, etc.

Question 23

What finding can be found if a revolver is used?

Answer 23

cylinder gap

- if cheap gun, some material will come out gap and cause secondary injury next to bullet hole

Question 24

Higher power guns

Answer 24

• more injury

- exit wound bigger than with handgun