The majority of a forensic scientist's time is spent collecting DNA evidence
studying science
testifying in court that the suspect is guilty
o investigating physical evidence

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).