Contamination

Question 1

What is contamination?

Answer 1

making something impure by exposure or addition of a polluting substance
(only counts if added after the crime occurred. if before = innocent transfer = adventitious transfer

Question 2

A contamination event

Answer 2

1. needs to be a source
2. needs an opportunity to occur
   (consumable to stain, person to stain, stain to stain)
3. needs mechanism for transfer to be achieved

Question 3

Drop- in

Answer 3

contamination where 1 or 2 alleles present in profile but not the extract (fallen in while preparing the sample)
eg dust particles in the lab