How do officer go about crime scene reconstruction?

Answer 1

They methodically collect evidence.

Answer 2

The first patrolman to arrive on the scene uses the crime scene tape to cordon off area. He also uses a marker of some sort to indicate which way is North for the investigators. A photo is taken (by photographer)of the scene before anyone goes in first.
In all crime scenes,someone either brought something or left with something. If bodies have to be removed a path is cleared so the paramedics can step on that path without disturbing evidence.

Answer 3

In a homicide for example, the victim may remain in the scene but not in the exact position at death. Of course the perpetrators are gone. If there have been gun shots, etc. there likely is blood spatter and footprints in the blood (estimating sex, size and weight of perpetrator and manufacturer of shoe). The body would be inspected for struggle and resistance (skin under fingernails or pulled hairs). Blood drains to the lowest portion of the body and remains there even if moved (libidity) after death. Core body temperature can help estimate the time of death (important to check alibis). Rods (or lasers) can be placed in bullet holes in walls to backtrack to the point where (several) shots were fired. Blood spatter (and mist) either on or under objects can help detect sequence of events and movements after the shooting. Answering machines are checked for recent messages and 'phone bills' for recent callers. Neighbors and witnesses may identify recent visitors or their vehicles or noise (arguments). Friendly or forced entry may help identify whether the perpetrator was known to the victim. The scene (now gone) must be reconstructed like a motion picture to document and extract any possibly useful clues. Did the perpetrator (a stranger) leave fingerprints (or DNA)? What likely is missing that might be found on a stranger.

Answer 4

sounds like the CSI shows are popular in here. Try this link
http://en.wikipedia.org/wiki/crime_scene