The authors describe the identification of 7 powders, supposed to be NPS, involved in a complex toxicological fatal case. The identification of these substances requires the development of a specific, quality and comprehensive method. However, it is difficult to obtain and purchase the reference standards of all substances. Some are excessively expensive, and some, even, do not exist in the catalogue of referenced suppliers. In addition to the difficulties associated with molecule characterization (identification, quantification, purity), analytical methods used routinely, such as LC-MS/MS, are not always sufficient to firmly identify NPS, for example in case of positional isomers. It is therefore necessary to use another method, such as NMR spectroscopy, to discriminate the species. The analytical strategy and the performance of NMR are developed in this article. The 7 powders were 4-chloro-α-pyrrolidinopentiophenone, dibutylone, 4-chloroethcathinone, 4-fluoro-α-pyrrolidinohexanophenone, 3,4-methylenedioxy-N-benzylcathinone, 3-methoxy-phencyclidine and α-pyrrolidinopropiophenone, with purity between 50.8 and 89.5%. There was no matching between the label and the active ingredient contained in the dispatched bags. This clearly demonstrates the danger in consuming substances bought on the internet, as both identity of the substance and its purity are missing.