Criminal Defense Practice Areas

Being accused of a crime can change every aspect of your life. Whether you have been arrested for a misdemeanor, charged with a serious felony, or believe you are under investigation, the decisions you make today may affect your freedom, your reputation, your career, and your future for years to come.

At Mark Diaz & Associates, criminal defense is not simply one of many practice areas. It is the exclusive focus of our practice. For nearly 30 years, we have represented clients throughout Galveston County, Harris County, and surrounding Texas communities in a wide variety of criminal matters ranging from first-time DWI arrests to complex felony prosecutions. Every case receives the same careful preparation because every client’s future deserves to be protected.

Below is an overview of the criminal defense services our firm provides. Each practice area presents unique legal issues, and every case deserves an individualized defense strategy built around the specific facts and evidence involved.

Comprehensive Criminal Defense Representation

Every criminal prosecution begins with an allegation, but allegations alone are not enough to obtain a conviction. Prosecutors must prove every element of a criminal offense beyond a reasonable doubt while complying with constitutional protections throughout the investigation.

At Mark Diaz & Associates, we begin by understanding how law enforcement developed the case, what evidence prosecutors intend to present, and whether that evidence was obtained legally. Depending on the circumstances, our review may involve witness statements, surveillance footage, forensic evidence, laboratory testing, search warrants, constitutional issues, and the procedures followed during the investigation.

No two criminal cases are exactly alike. Some involve isolated incidents. Others result from lengthy investigations conducted by multiple law enforcement agencies. Rather than applying the same strategy to every client, we develop a defense based on the facts unique to each case.

DWI Defense

Driving while intoxicated remains one of the most commonly prosecuted criminal offenses in Texas, but no two DWI investigations are exactly alike. Some arrests involve alcohol, while others involve prescription medication or controlled substances. Some begin with routine traffic stops, while others follow accidents or roadside investigations. The evidence may include field sobriety testing, breath testing, blood analysis, body camera footage, witness statements, or a combination of several different types of evidence.

Because every investigation is different, every defense should be different as well. Our firm carefully evaluates the legality of the traffic stop, the administration of field sobriety tests, chemical testing procedures, constitutional issues, and every other aspect of the investigation before recommending a defense strategy.

We represent clients facing a wide variety of DWI-related offenses, including:

Whether this is your first arrest or you have prior convictions, every case deserves an independent review. An arrest does not automatically mean a conviction, and every investigation should be carefully examined to determine whether law enforcement complied with Texas law and whether prosecutors can prove every element of the offense. Understanding the potential DWI penalties in Texas and how issues such as refusing a breath test may affect both your criminal case and your driving privileges is an important part of evaluating your legal options.

Drug Crimes

Drug crime allegations range from simple possession cases to complex felony prosecutions involving multiple defendants and lengthy investigations. The penalties vary significantly depending on the type of controlled substance involved, the quantity recovered, prior criminal history, and whether prosecutors believe distribution or manufacturing occurred.

Many drug investigations begin long before an arrest is made. Law enforcement agencies may rely on confidential informants, surveillance, controlled purchases, search warrants, electronic communications, financial records, or information gathered during unrelated investigations. By the time charges are filed, prosecutors often believe they have assembled a strong case.

That does not mean the investigation was conducted lawfully.

At Mark Diaz & Associates, we carefully evaluate how evidence was obtained, whether constitutional rights were protected, and whether prosecutors can actually establish possession, intent, or distribution beyond a reasonable doubt.

Our firm represents clients facing a wide range of drug-related offenses, including:

Every drug case presents different legal issues. Some focus on unlawful searches. Others involve disputed possession, confidential informants, laboratory testing, or whether the prosecution can prove intent to distribute. Rather than assuming every drug case should be defended the same way, we build a strategy based on the specific evidence involved in your case.

If you have been arrested for a drug offense or believe you are under investigation, seeking legal representation early often provides the greatest opportunity to preserve evidence, protect your constitutional rights, and begin preparing an effective defense.

Violent Crimes

Violent crime allegations are among the most aggressively prosecuted offenses in Texas. A conviction can result in lengthy prison sentences, substantial fines, and lifelong consequences that extend well beyond the courtroom. At the same time, many violent crime cases are far more complicated than they first appear. Witnesses often provide conflicting accounts, physical evidence may not support the allegations, and law enforcement officers are frequently asked to make decisions based on incomplete information during highly emotional situations.

Our firm approaches every violent crime case by carefully examining the evidence rather than accepting the prosecution’s version of events at face value. We review witness statements, surveillance footage, forensic evidence, medical records, body camera video, and every other available piece of evidence to determine whether prosecutors can prove their case beyond a reasonable doubt.

Our firm represents clients facing a wide range of violent crime allegations, including:

Every violent crime prosecution presents different legal and factual issues. Whether the defense involves self-defense, mistaken identity, witness credibility, constitutional violations, or weaknesses in the prosecution’s evidence, we build our strategy around the specific facts of your case rather than relying on a one-size-fits-all approach.

Burglary, Robbery & Theft

Although burglary, robbery, and theft are often discussed together, they are distinct criminal offenses under Texas law that carry different elements and different penalties. A conviction can affect your employment opportunities, professional licensing, educational goals, and future long after a criminal sentence has been completed.

Many of these cases depend on surveillance video, eyewitness testimony, forensic evidence, or statements obtained during police interviews. Our firm carefully reviews how the investigation was conducted, whether evidence was lawfully obtained, and whether prosecutors can establish every element required for a conviction.

If you have been charged with burglary, robbery, theft, or another property crime, we will thoroughly evaluate the evidence while working to protect your rights and pursue the strongest possible outcome. Learn more about our approach to burglary, robbery, and theft defense.

White Collar Crimes

White collar crime investigations often begin months or even years before charges are filed. Unlike many criminal cases that result from a single incident, financial crime investigations frequently involve extensive document review, electronic records, banking information, business transactions, and communications between multiple individuals.

These cases can be highly complex, requiring a careful understanding of both the underlying financial records and the criminal allegations being made. Whether the investigation involves fraud, embezzlement, forgery, identity theft, or another financial offense, prosecutors must still prove every element of the alleged crime beyond a reasonable doubt.

Our firm carefully reviews the evidence, identifies weaknesses in the government’s case, and develops a defense strategy tailored to the specific allegations. Learn more about our white collar crime defense services.

Federal Criminal Defense

Federal criminal cases differ significantly from prosecutions filed in Texas state courts. They are investigated by federal agencies, prosecuted by Assistant United States Attorneys, and governed by different procedural rules and sentencing guidelines. Federal investigations often involve months of preparation before an arrest ever occurs.

Our firm represents clients facing a variety of federal criminal allegations, including federal drug offenses, firearm charges, fraud offenses, conspiracy allegations, and other complex criminal matters prosecuted in federal court.

If you have reason to believe you are the subject of a federal investigation, seeking legal counsel as early as possible can be critical. Early representation may allow your attorney to communicate with investigators, preserve important evidence, and begin preparing your defense before formal charges are filed.

Learn more about our federal criminal defense services.

Expungements

Not every criminal matter ends with a conviction, and in some situations, individuals may be eligible to clear certain arrests or criminal records from public view.

An expungement can provide valuable opportunities for people seeking employment, housing, professional licensing, or educational advancement. However, Texas law establishes specific eligibility requirements, and not every case qualifies.

Our firm helps clients evaluate whether they may qualify for an expungement and guides them through the legal process from beginning to end. If you have questions about clearing your criminal record, we encourage you to learn more about Texas expungements and whether this legal remedy may be available in your situation.

Why Choose Mark Diaz & Associates?

Choosing a criminal defense attorney is one of the most important decisions you will make after an arrest. Experience matters, but so do preparation, communication, and accessibility.

For nearly 30 years, Mark Diaz & Associates has focused exclusively on criminal defense. That singular focus allows our firm to stay current on developments in Texas criminal law while providing clients with defense strategies built around careful preparation and a thorough understanding of the evidence.

Every client receives straightforward advice, honest communication, and a defense tailored to the unique facts of the case. Whether your matter involves a misdemeanor, a serious felony, or a complex federal investigation, our commitment remains the same: protect your constitutional rights while pursuing the strongest possible outcome under the law.

Speak With a Galveston Criminal Defense Attorney Today

If you have been arrested or believe you are under investigation, do not wait to seek legal guidance. The earlier a criminal defense attorney becomes involved, the greater the opportunity to preserve evidence, identify legal issues, and begin building an effective defense strategy.

For nearly 30 years, Mark Diaz & Associates has represented clients throughout Galveston County, Harris County, and surrounding Texas communities facing a wide variety of criminal charges. We offer free consultations, complimentary parking at our Galveston office, and bilingual assistance for Spanish-speaking clients. Se habla español.

Whether you need representation for DWI charges, drug crimes, violent crimes, white collar crimes, federal criminal defense, expungements, or another criminal matter, our firm is prepared to evaluate your case and explain your legal options.

Call 409-515-6170 today to schedule your free consultation with Mark Diaz & Associates.