By Ulises Flores Luna — Criminal defense attorney with twelve years of experience in the Federal Judiciary, where he reached the position of District Judge in criminal matters through judicial career competitive examination.
No one expects to be involved in a criminal matter, but the reality is that any citizen can be. That is why knowing your rights is not optional — it is a tool that can make the difference.
Today I explain something fundamental: Having a lawyer is a right. Having them defend you well is also a right.
From when can you request a lawyer?
From the very first moment. As soon as a person is detained, informed that they are under investigation, or acquires the status of accused, they have the right to a licensed attorney with a professional license. You do not have to wait to appear before a judge, or to be “processed.” It is a right that arises even at the moment of detention.
(Legal basis: Article 20, Section B, fraction VIII of the Constitution)
And if I cannot afford a lawyer?
It does not matter. The State has the obligation to assign you one free of charge. Any intervening authority — police, Public Prosecutor’s Office, judges, or magistrates — has the obligation to make that right effective.
In other words: You should never face a criminal process without legal defense, regardless of your economic situation.
(Legal basis: Article 20, Section B, fraction VIII of the Constitution)
What happens if this right is not respected?
The consequences are serious — but in your favor. If, for example, a statement or interview was taken from you without your lawyer present, that act may be declared null. That is, as if it had never existed.
This is important because it protects that no one is pressured to make statements against themselves without the support of someone who defends them.
(Legal basis: Article 20, Section B, fraction II of the Constitution and Article 114 of the National Code of Criminal Procedure)
Having a lawyer is not enough: They must defend you well
It is not enough to have a professional license; that is only the first requirement of a technical defense to intervene in a criminal process. In addition, the defense must be carried out effectively, meeting a minimum standard of diligence in the performance of duties, which must be monitored by the judge in their capacity as guarantor and director of the criminal process.
How do you know if your defense is failing?
The Supreme Court of Justice of the Nation has identified concrete warning signs that may indicate you are not receiving an adequate defense:
- — That your lawyer does not offer evidence without apparent reason.
- — That they remain silent when they should speak.
- — That they do not file remedies when the law allows it.
- — That they do not advise you about your options.
- — That they show they do not know the criminal procedure.
- — That they simply do not appear or abandon your case.
If you identify any of these signs, do not ignore them.
What can you do?
The first thing is to ask yourself whether that failure was an oversight or part of the strategy agreed with you. The difference matters: If the problem came from the defender and not from a decision of yours, you have the right to act.
The most direct answer: Change lawyers. If it is a private attorney, you can hire a new one. If it is a public defender, you can formally request the change, explaining the reasons.
Who else must ensure that your defense is real?
Not only you. The Public Prosecutor’s Office and the Judge in charge of the criminal process also have the obligation to monitor the proper performance of defenders and, in the face of a breach of their obligations, must relieve them of their duties.
(Legal basis: Article 20, Section B, fraction VIII of the Constitution and Article 121 of the National Code of Criminal Procedure)
In upcoming installments we will continue talking about other rights that every citizen should know.
"If you or someone in your family is facing a criminal situation and has doubts about whether they are receiving an adequate defense, at Flores Rodríguez y Asociados we can review your case. Knowing the process from the judge’s perspective allows us to accurately assess whether the defense is fulfilling its function — and what can be done about it."
¹ Direct amparo under review 3678/2024, resolved by the First Chamber of the Supreme Court of Justice of the Nation, approved on February 19, 2025, by 4 votes; and amparo under review 370/2025, resolved by the Full Court of the Supreme Court of Justice of the Nation, approved on January 27, 2026, by unanimous vote.
Ulises Flores Luna
Criminal defense attorney. Twelve years of experience in the Federal Judiciary, where he reached the position of District Judge in criminal matters through judicial career competitive examination.