Diatom Test – Conclusive Medico-Legal Evidence in Decomposed Drowning Cases

During medico-legal autopsies of decomposed bodies, it is difficult to ascertain ante-mortem drowning. In such cases, positive diatom test provides strong conclusive evidence. In the present study diatom test was applied on 22 decomposed bodies to corroborate the alleged history and/or circumstantial evidence of ante-mortem drowning in fresh water during the two-year period from 7^th August 2003 to 6^th August 2005 at Forensic Medicine Department of P.D.U. Medical College, Rajkot, (Gujarat). The test was positive for 21 cases (90.90%) and negative for one case (4.55%). In one case (4.55%), the diatoms were detected neither in the bone marrow (from intact sternum) nor in the putative drowning medium (fresh water). It was further noticed that advanced decomposition states, seasonal variations and mobility of the water has no effect on the validity of the test. In addition to the ante-mortem drowning factor, diatoms also played an important role in confirmation of the place of drowning.