This is Guatemala where "... Penal de Instrucción" > Criminal Magistrates' Court

https://www.cidh.oas.org/annualrep/2006eng/GUATEMALA.11171en...
23. The State of Guatemala stated in its initial response that an investigation has been started as part of Proceedings No. 79-93 in the ***Juzgado Segundo de Primera Instancia Penal de Instrucción [Second Criminal Magistrates’ Court of the First Instance]*** and that several procedures towards clarifying the facts were pending. It further informed the IACHR that the Ministry of National Defense and the Office of the Attorney General had been instructed to investigate the case and to move the proceedings forward.

The judicial system, whether state or federal, begins with a court of first instance, whose work may be reviewed by an appellate court, and then ends at the court of last resort, which may review the work of the lower courts.
( http://en.wikipedia.org/wiki/List_of_courts_of_the_United_St... )

The State Court System Structure usually consists of a three tier system. The court of first instance or the primary courts for initial hearing are the district courts. The nomenclatures for these courts vary from state to state and the Structure of the State Court enables each state to name its basic court as district, municipal or superior courts. Circuit courts form the courts of first instance in the states of Arkansas, Illinois, Florida and Alabama. The only exception is the state of New York. The State Court Structure Charts show that the Supreme Court is the court of first instance here.
( http://cariinfo.pe.hu/look/New_York_Court_Structure/State_Co... )

"Court of first instance" is defined as "The initial trial court where an action is brought." This stands in contrast to an appellate court, defined as "a court of last instance".