Should Spain's Guardia Civil be subject to military justice?

A case from the Canary Islands has raised an interesting recurring question: should personnel of the Guardia Civil be subject to military justice, even though the Guardia is not part of Spain's armed forces? Here is the story according to El Confidencial Digital. In other countries with militarized police forces (e.g., Chile's carabineros), the concern has been whether victims of police misconduct can get a fair shake from military courts. Here, in contrast, it is a question of internal discipline not affecting members of the public: the accused is simply charged with insulting a superior. The controversy could wind up at the European Court of Human Rights.