On October 18th 2019, a period of protests began in Chile called the "social outbreak" that led to mass demonstrations and the occurrence of criminally prosecutable behaviors. This exploratory study analyzes the functioning of arrests' control hearings during the social outbreak, using as analytic framework the "fair treatment" concept provided by procedural justice literature, and administrative data from the Public Criminal Defense Office and 68 interviews conducted with people arrested during those protests. The results show substantial increases in the daily number of arrestees and defendants without previous contact with the penal system, as well as an increase in the proportion of declarations of illegality of the arrests and of the precautionary measures decreed. It is also noted that although prosecutors, defenders and judges did comply with legality, part of the defendants perceived that the criminal justice system did not provide them with adequate treatment.. The study discusses which of these situations are linked to the context generated by the social outbreak and which are manifestations of older problems in the penal system, and how the problems surrounding arrestee treatment ascertained can affect the perceived legitimacy of the penal system.