[1] As lieutenant colonel, he advised the Institutional Security Bureau of the Presidency of the Republic (2000–01) and commanded the 1st Battalion of Special Forces in Goiânia, in the (2005–06).

[1] Arruda was put in charge of the Brazilian army under Jair Bolsonaro on 30 December 2022, replacing Marco Antônio Freire Gomes.

[2] On 8 January, pro-Bolsonaro rioters attacked federal buildings at the Praça dos Três Poderes in Brasília, many calling on the military to overturn the election results in which Jair Bolsonaro lost to Luiz Inácio Lula da Silva.

[4] The officials were faced tanks and lines of soldiers, and Júlio Cesar de Arruda told Minister of Justice Flávio Dino: "You are not going to arrest people here.

]"[5] Lula relieved Arruda of his post as commander of the army on 21 January 2023, replacing him with Tomás Miguel Ribeiro Paiva [pt].