What Does a Criminal Defense Attorney Do?

When you’re facing criminal charges in California, understanding what a criminal defense attorney actually does can make the difference between confusion and confidence. These legal professionals do far more than just show up in court—they become your advocate, strategist, and guide through one of the most stressful experiences you’ll likely face.

Let’s break down exactly what these attorneys do and why their work matters so much to your case.

Protecting Your Rights from Day One

The moment you’re arrested, your constitutional rights are at stake. A criminal defense attorney’s first job is making sure law enforcement and prosecutors respect those rights.

Your attorney protects three critical constitutional rights:

Fourth Amendment – Illegal Searches and Seizures

If police searched your car, home, or phone without proper legal authority, your attorney can file motions to suppress that evidence. Without that evidence, prosecutors often can’t prove their case.

Fifth Amendment – Self-Incrimination

Defense attorneys advise clients on when to remain silent and when speaking might help. They’re also the buffer between you and aggressive questioning tactics.

Sixth Amendment – Legal Representation and Fair Trial

Your attorney ensures prosecutors follow proper procedures, disclose evidence, and don’t violate your due process rights.

Many people don’t realize how easily these rights can be violated during an arrest or investigation. Having someone who knows the law and can spot violations is invaluable.

Investigating Your Case Independently

Prosecutors have police investigators and resources working for them. Your defense attorney levels the playing field by conducting an independent investigation.

This might include:

• Interviewing witnesses the police didn’t talk to (or talked to but didn’t document properly)
• Visiting the crime scene to look for details that contradict the prosecution’s version
• Obtaining surveillance footage before it’s deleted or recorded over
• Hiring forensic experts to challenge DNA, fingerprints, or other technical evidence
• Reviewing police reports for inconsistencies or procedural errors
• Gathering character references and evidence of your background

At The Nieves Law Firm, we have an in-house private investigator on staff. Having this resource built into our team means we can start investigating immediately.

Building Your Defense Strategy

Every case is different, and your attorney’s job is crafting a defense strategy tailored to your specific situation.

Common defense strategies include:

• Challenging the evidence. This means questioning whether physical evidence was collected properly, if witness testimony is reliable, or if forensic results were interpreted correctly.
• Proving lack of intent. Many crimes require prosecutors to prove you intended to commit the offense. If they can’t prove intent, they can’t get a conviction.
• Establishing alibis. If you weren’t at the scene when the crime occurred, your attorney gathers evidence proving you were somewhere else.
• Self-defense or defense of others. In assault or battery cases, showing you acted to protect yourself or someone else can be a complete defense under California law.
• Mistaken identity. Eyewitness identification is notoriously unreliable. Your attorney can challenge whether witnesses correctly identified you.
• Violations of your rights. If police violated your constitutional rights during the investigation, your attorney can get evidence thrown out or charges dismissed.

The strategy isn’t just about what happened—it’s about what the prosecution can prove beyond a reasonable doubt.

Negotiating With Prosecutors

Most criminal cases don’t go to trial. They’re resolved through plea negotiations, where your attorney works with prosecutors to reach an agreement.

This doesn’t mean just accepting whatever deal prosecutors offer. Your attorney negotiates for:

• Reduced charges (a felony reduced to a misdemeanor, for example)
• Lesser penalties (probation instead of jail time)
• Dismissal of certain charges in multi-count cases
• Alternative sentencing, like diversion programs or rehabilitation
• Agreements that protect your immigration status, professional licenses, or gun rights

Prosecutors respect attorneys who know the law and aren’t afraid to take cases to trial. When your attorney has a strong defense strategy, prosecutors are more likely to offer favorable deals.

The negotiation process requires understanding the strengths and weaknesses of both sides. Your attorney knows when an offer is fair and when to push back.

What Criminal Defense Attorneys Do in Court

When cases do go to court, your defense attorney handles multiple types of proceedings:

• Arraignment: Your first court appearance, where charges are formally read, and you enter a plea.
• Bail hearings: Arguments for your release from custody while the case is pending.
• Preliminary hearings: For felonies, the prosecution must show probable cause that you committed the crime. Your attorney can challenge their evidence and cross-examine witnesses.
• Pretrial motions: Legal arguments asking the judge to dismiss charges, suppress evidence, or rule on legal issues before trial.
• Trial: If your case goes to trial, your attorney selects the jury, presents opening statements, cross-examines prosecution witnesses, presents defense witnesses and evidence, and delivers closing arguments.

Throughout these proceedings, your attorney is making strategic decisions about which arguments to raise, which witnesses to call, and how to present your case most effectively.

Handling the Legal Paperwork and Deadlines

The criminal justice system runs on paperwork and strict deadlines. Missing a filing deadline or submitting incorrect documents can seriously harm your case.

Your defense attorney handles:

• Filing motions and legal briefs
• Responding to the prosecution’s motions
• Submitting discovery requests
• Preparing witness lists
• Filing appeals if necessary
• Managing court deadlines and scheduling

This administrative work might seem boring, but it’s critical. Courts don’t accept excuses for missed deadlines, and procedural mistakes can cost you your freedom.

Advising You Throughout the Process

Beyond the legal work, your attorney serves as your advisor and counselor during an incredibly stressful time.

They explain:

• What charges you’re facing and what they mean
• Potential penalties if convicted
• The strength of the prosecution’s case
• Your realistic options and likely outcomes
• Whether to accept a plea deal or go to trial
• What to expect at each stage of the process

Criminal defendants often face pressure from family, friends, and prosecutors—all giving conflicting advice. Your attorney gives you objective, legally sound counsel based on their experience.

Post-Conviction Representation

Even after a case concludes, criminal defense attorneys can continue helping with:

• Filing appeals based on legal errors during trial
• Seeking sentence modifications or early termination of probation
• Expungement of criminal records under California Penal Code § 1203.4
• Restoration of rights (like gun rights or professional licenses)
• Immigration consequences of convictions

This post-conviction work can significantly impact your future, especially when it comes to employment, housing, and other opportunities.

Why Experience Matters in Criminal Defense

Not all criminal defense work is the same. Attorneys who regularly handle cases in California courts develop relationships with prosecutors and judges, understand local procedures, and know which arguments work in specific courtrooms.

At The Nieves Law Firm, our team has handled hundreds of criminal cases throughout the Bay Area. We know the prosecutors, we know the judges, and we know how to get results in California’s criminal justice system.

We’re one of the largest criminal defense firms in the Oakland-Bay Area, which means we have resources smaller firms can’t match.

Get the Defense You Deserve

Facing criminal charges means your freedom, reputation, and future are at stake. You need an attorney who will fight for you at every stage of the process—from investigation through trial and beyond.

The Nieves Law Firm provides aggressive, prepared defense for working professionals caught up in California’s criminal justice system. We show up to win, and we’re not afraid to take your case to trial when that’s the best option.

Contact us today at The Nieves Law Firm for a complimentary consultation. Let’s discuss your case and start building your defense immediately.