You are investigating the scene of a hit and run where somebody's pet dog was killed. It is a very hot day so the dog's body temperature is unlikely to yield any important information regarding the time of death. The dog's limbs are movable and there is no significant smell of rotting flesh. What is the best guess of the time of death?

Question

A.  within the last 10 minutes
B.  within the last 2 hours
C.  3-4 hours ago
D.  24 hours ago

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?

Gather Content
· What do you know about rigor mortis? What other information is related to the question?

Choose Answer
· Given what you now know, what information is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  within the last 10 minutes

Clarify Question
· What is the key concept addressed by the question?
        o The question asks about rigor mortis.
· What type of thinking is required?
        o You are being asked to apply your knowledge about rigor mortis.

Gather Content
· What do you know about rigor mortis? What other information is related to the question?
        o In death, the cell can no longer produce ATP, and therefore the cross-bridge cycle cannot be broken—causing the muscle stiffness of death called rigor mortis. A living cell, however, always has enough ATP to allow the myosin heads to detach from actin. It takes several minutes for the cells to use up their supplies of ATP in the absence of oxygen. Once established rigor mortis will persist for about 12 hours. Decay will not begin for a day or two after death.

Choose Answer
· Given what you now know, what information is most likely to produce the correct answer?
        o Rigor mortis would set in about an hour after death, since the dog is not in rigor mortis yet it probably died within the past 10 minutes. If the dog had died between 1-12 hours earlier it would be in rigor mortis. After 12 hours it would be relaxed again, but decay may start to occur.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question asked you to apply your knowledge about rigor mortis. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you think that rigor mortis would allow the limbs to still be moveable? Did you think that rigor mortis would not occur for 12 hours after death?