Cocaine toxicological findings in cases of violent death in Sao Paulo city - Brazil.

Violence is a dreadful phenomenon spread throughout the world, resulting in unfortunate events that can ultimately cause death. It is known that some countries play a much worrying role in this scenario than others. Brazil is one of them. The present work has focused on identifying the use of cocaine in 105 postmortem cases arriving at the Institute of Legal Medicine of Sao Paulo (IML-SP), the largest Brazilian city. Both blood and hair samples have been analyzed through ultra-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) in order to distinguish between recent or chronic cocaine use. The purpose of this work was to evaluate the proportion of cocaine use amongst violent individuals whose violence has ultimately led to their death. In order to do so, two previous methods, validated in-house, based on methanolic extraction for hair and protein precipitation for blood, have been used for this purpose and the final residue was analyzed through UPLC-ESI-MS/MS system. When looking at the demographics from the 105 postmortem cases analyzed, the results have shown the most critical age range to be between 18 and 25 years old and the least frequent between 37 and 45 years old. Gender wise, a rather extreme difference was found as 97 of the individuals were men and finally, considering the manner of death, the four-category criteria established appear to be fairly similar with 34 cases related to general violence and risk behavior, 26 to drug abuse suspicion, 23 to homicide resulting from opposition to police intervention and 22 to possible suicide.