Other forms of evidence Flashcards
what is chromatography
A method of separation and analysis of a mixture of soluble chemical substances. The solvent travels up the paper by capillary action.
features of handwriting
Spacing of letters and words
Slant of letter
Pressure on the page
Formation of the loops in letters such as L, O, f, p, B etc
Dotting of the letter “I, j”
Crossing of the letter “t”
What is DNA profiling?
when biological evidence can be taken from a crime scene and
analysed, then compared to the profiles of known offenders who are already in criminal DNA
databases.
How is DNA profiling done
DNA is removed from the sample. Separating enzymes cut the DNA into small pieces at specific points.
The pieces of DNA from different samples are lined up
across a jelly-like substance.
When electricity is passed through the sample, the pieces
of DNA spread across the jelly-like substance. As the
pieces spread, they form a pattern on the autograph.
DNA samples collected from a suspect go through the
same process as the sample from the crime scene.
The autograph is for matching pieces of DNA from the
different samples.
DNA can be taken from what part of a cell (which organelle)?
the nucleus
Different types of blood splatter
A smear shows that something was possibly dragged.
An arc of blood splatter forms when the victim pulls away from an impact.
Lines of spotted blood shows that an object was possibly swung and put blood onto nearby surfaces.
Can twins have the same DNA profile?
No, as only identical twins can have the same DNA profile
What should happen to the DNA of an individual who is cleared of a crime?
The sample is physically destroyed by biohazard destruction, while the profile is deleted from the electronic database and all paper references to it are destroyed.
