In the context of Judiciary or Forensic Linguistics, this paper shows the results of a study on rhotic consonants in prepausal position (in the spontaneous speech of central peninsular Spanish) in order to assess their forensic value for identifying speakers. The variables that have been analysed are the number of components and the acoustic features of the first and second components of the consonant, which correspond to the closure and opening phases, respectively. The results have shown some significant differences amongst speakers, which is why the rhotics are considered a useful segmental element in comparing speech samples on judiciary purposes