Forensic Medicine important study Notes

Typical-Knot at the occiput
Atypical-Knot at any place other than occiput
Complete-Fully suspended in air
Partial-Feet touching the ground
 

Homicide

Garroting- Ligature strangulation from behind
Mugging- By holding neck in the bend of elbow
Burking-Smothering+Traumatic asphyxia
Force required to obstuct trachea-15kg

Fresh water and salt water drowning

Fresh water drowning-Hemodilution,hyponatremia,Hyperkalemia
Salt water drowning-Pulmonary edema,hemoconcentration
Hydrocution- No specific postmortem finding
Water in sphenoidal air sinus  is a very good sign in drowning.

Rule of Hasse

To find intrauterine age of fetus
Upto 5 months square root of length
After 5 months multiply by 5.
Ossification centres
Viability attained by 7 months/210 days

Ossification center in calcaneum-5 months
Ossification center in talus-7 months
Ossification center in cuboid-9 months
Strenum- 5 ossification centers(66779) if atleast 3 is present, fetus is viable.
Testamentary capacity-Ability to make a will

Caspers dictum

Rate of decomposition in soil water and air- 1:2:8
“According to an old rule of thumb (Casper’s dictum) one week of
putrefaction in air is equivalent to two weeks in water, which is equivalent to eight
weeks buried in soil, given the same environmental temperature”.

Criminal responsibility of insane

Durham’s rule
Currens rule
Mcnaughtens rule
First permanent tooth to erupt-First molar
Thanatology-Science of death
Sommer’s movement-Due to shortening and stiffening of muscles in rigor mortis.
Proximal 2 cm of anterior descending branch-Commonest site of MI
Rigor mortis is due to-reduction of ATP
Marbling-Branching pattern of veins after death-Can be seen by 36 hours
Clostridium welchii-Adipocere, foamy liver.
Evidence of recent sex in male-Lugol’s iodine test.

Chemical tests

Seminal stains-Florence,acid phosphatase test,Barberio test
Blood stains-Takayama test
Blood grp of old blood stain-Absorption elution technique
Christmas Y stain-Detects sperm in vaginal mucosa.
Nystens Law-Spread of rigor mortis-proximo distally.

Sex determination

1. Ischiopubic index
2. Sacral index
3. Corporobasal index(Diameter of sacrum)
4. Medullary index(Bone)

Race determination

1. Brachial index(radius/humerus)
2. Crural index(tibia/femur)
3. Humerofemoral index
4. Cephalic index

Age determination

1. Costochondral junction
2. Pubic symphisis
3. Gustafson’s method

Medullary index of hair-Species determination
Fragmented medulla-negroid
Humans have narrow medulla-type 7.

Cephalic index

70-74.9-Dolicocephalic(Negroes,aryans)
75-79.9-Mesaticephalic(Europeans,chinese)
80-84.9-Brachycephalic(mongolians)
Bertillion system-Antopometry
Dalton system-Dactylography