The judiciary is divided into federal and state systems. Federal courts have jurisdiction over major felonies, including drug trafficking. In the federal system, judicial power is exercised by the Supreme Court of Justice, circuit courts, and district courts (see Judicial, ch. 4). The first chamber of the Supreme Court, composed of a president and four other judges, deals with penal affairs. Twelve collegiate circuit courts, each with three magistrates, deal with the right of amparo (constitutional rights of an individual, similar to habeas corpus). Nine unitary circuit courts, of one magistrate each, deal with appeals. There are sixty-eight one-magistrate district courts. State judiciary systems following a similar pattern are composed of state supreme courts, courts of first instance, and justices of the peace or police judges.

In most instances, arrests can be made only on authority of a judicial warrant, with the exception of suspects caught in the act of committing crimes. Suspects often are arrested without warrants, but judges tend to overlook this irregularity. Those arrested are required to be brought before an officer of the court as soon as possible, generally within forty-eight hours (ninety-six hours when organized crime is alleged), whereupon their statements are taken and they are informed of the charges against them. Within seventy-two hours of arraignment, the judge must remand the arrested person to prison or release him or her.

Criminal trials in nearly all cases are tried by a judge without a jury. The judge acting alone bases his or her verdict on written statements, depositions, and expert opinion, although in some instances oral testimony is presented. Defendants have access to counsel, and those unable to afford legal fees can be assigned public defenders. The quality of pro bono counsel is often inferior. The accused and his or her lawyer do not always meet before trial, and the lawyer may not appear at the important sentencing stage. The right to a public trial is guaranteed, as is the right to confront one's accusers and to be provided with a translator if the accused's native language is not Spanish. Under the constitution, the court must hand down a sentence within four months of arrest for crimes carrying a maximum sentence of two years or less, and within one year for crimes with longer sentences.

The entire process--the time for a trial, sentencing, and appeals--often requires a year or more. According to Amnesty International, a large number of persons charged with crimes have been held far beyond the constitutional limits for their detention. The long trial process and the detention of those who cannot qualify for or make bail are major causes of crowded prison conditions.

The penal code stipulates a range of sentences for each offense. Sentences tend to be short, in most cases not longer than seven years. The actual time of incarceration is usually three-fifths of the sentence, assuming good behavior. Those sentenced for less than five years may avoid further time in jail by payment of a bond.