 The results were then used to get confessions from the suspects.When using diatom testing, scientists observe the amount of diatoms present on the organism and may be able to estimate a generalized time of death.If there are less than 20 different species of colonizing diatoms, then the organism's death could have been within the previous 7 to 12 days, but, if there are more than 50 different colonies of diatoms then it is determined that death possibly occurred several weeks ago.