Drawing on Brown and Fraser’s (in: Giles, Scherer (eds) Social markers in speech, Cambridge University Press, Cambridge, pp 33–62, 1979) framework for the analysis of communicative situations and Fuentes Rodríguez’s (Lingüística pragmática y Análisis del discurso, Arco Libros, Madrid, 2000; in Estudios de Lingüística: Investigaciones lingüísticas en el siglo XXI, 2009. https://doi.org/10.14198/ELUA2009.Anexo3.04) model of pragmatic analysis, this paper examines three home-made recordings featuring some of the members of the terrorist cell responsible for the 2017 vehicle-ramming attacks in Barcelona and Cambrils weighted as evidence during the trial held between November 2020 and May 2021 in the Spanish National High Court. The aim of this qualitative analysis is to test whether the linguistic evidence available supports the allegation that the participation in these recordings by one of the accused, Mohamed Houli Chemlal, had been planned by his interlocutors. Results show, first, that the exchanges analyzed present features indicative of both spontaneity and (limited) planification. Second, that Houli makes key contributions to the unfolding of the interactions shown in the recordings and that he does so in a cooperative and apparently relaxed manner, which could at best provide only partial support to his allegations. It is claimed that forensic linguistic analysis can generate valuable insights within terrorism-related legal proceedings.