According to Amnesty International: "State efforts to repress the rights to freedom of expression, assembly and association have intensified during a period that has encompassed a highly contested Presidential election, attacks by Boko Haram and a severe ongoing economic crisis provoked by a sharp drop in the price of crude oil. [...] In a growing number of cases, because of the history of banning assemblies, associations have decided to organize peaceful demonstrations without notifying the authorities nor seeking prior authorization. In most cases, they have just communicated about their plans through press conferences, public statements or social media. This is something they should be able to do, according to international treaties ratified by Chad, without rendering the assembly unlawful. However, in such cases, the authorities have resorted to the use of excessive force – beating [...] protesters, using tear gas and in some cases using live ammunition – to break up peaceful protests and arrest protesters. [...] This came after security forces dispersed a students’ demonstration in N’Djamena on 9 March 2015, which had been organised been to oppose a government decision to enforce the mandatory wearing of helmets for all motorcyclists. According to the Chadian Human Rights League (Ligue Tchadienne des Droits de l’Homme, LTDH), over 200 people were arrested during the demonstration. Some students had been throwing stones, and were accused by authorities of having set fire to a bus, and in response the police fired tear gas into the crowd and into a university compound. In the ensuing panic, students were injured and witnesses claim that a student, Hassan Daoud, was run over by a police vehicle. Amnesty International sent a photo of Hassan’s body to be analysed by a forensic expert, who confirmed that the head injury shown could be consistent with the type of injury sustained by being run over by a vehicle. There was no inquiry into his case and the Public Prosecutor denied any death during the protest. Following national and international pressure, a judicial inquiry was opened into the ill-treatment of the arrested students and on 20 May 2015, the N’Djamena High Court sentenced eight police officers to six months in prison and fined them XAF50,000 (US$90) for illegitimate violence, wilful assault and complicity. Six other officers were acquitted. A GMIP Commander identified by the students as giving the orders for the ill-treatment was not prosecuted. The Public Prosecutor explained Amnesty International that there was no reasons to prosecute the GMIP Commander as he was not shown on the video and witness testimonies exonerated him." ^[+]