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Houston Assault Attorney

Assault Attorney With 38 Years of Experience

Are you looking for an experienced Houston assault attorney to help you defend assault and aggravated assault charges? With over 38 years of experience, assault defense attorneys John P. Keirnan and Michael Mercer provide aggressive criminal defense for all assault charges, including assault family violence, assault bodily injury, aggravated assault charges and sexual assault charges. We protect our clients from false allegations and work closely with them to make sure their side of the story is heard. 

The accused in an assault case rarely gets the chance to tell their side of the story before being arrested, leaving the police officer to do his own storytelling. Houston assault attorney John Keirnan is not intimidated by the police. He works side by side with each client to make sure that their side of the story is heard. Discuss your assault or aggravated assault charge with an experienced Houston assault defense attorney. Call 713-236-9700 for a free consultation.

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Experienced Houston Assault Lawyer

(713) 236-9700

  Assault Attorney Casey Keirnan Stands Up Against False Accusations

Client Reviews


Average Rating: 5 out of 5 (11 reviews)

"I hired Mercer and Keirnan because of their experience handling DWIs and other charges.  Working closely with them throughout my case, it became very clear that I had made the right decision..."

by T. M. December 30, 2018

Defense Attorney for Aggravated Assault Charges

If you or someone you know has been charged with aggravated assault with serious bodily injury, take advantage of our free consultation services and contact a knowledgeable defense attorney for aggravated assault charges at (713) 236-9700. 


Aggravated Assault with a deadly weapon is a second degree felony. A person commits aggravated assault with a deadly weapon if that person uses or exhibits a deadly weapon during the commission of an assault. Nearly any object can qualify as a deadly weapon depending on how it is used. Contact a Houston Assault Defense Attorney at (713) 236-9700 to find out how to defend your aggravated assault case.


Aggravated Assault with serious bodily injury is a second degree felony, punishable by up to 20 years in prison and a $10,000.00 fine. "Serious bodily injury" is injury that creates a substantial risk of death, serious permanent disfigurement, or protracted loss or impairment of the function of any bodily member or organ. 

Assault Family Violence Charges

Domestic violence charges, also known as "domestic assault", "family violence" or "assault bodily injury family member", are among the most common types of assault charges. Domestic violence charges are prosecuted very aggressively in Houston, weather or not the complaining witness wishes to drop the charges. Anyone arrested or charged with domestic violence in Houston should speak with an experienced domestic violence lawyer before appearing in court. There are often defenses to family violence charges that an experienced assault defense attorney can use to get your domestic violence charge dismissed.


"Family Violence" is defined broadly in section 71.004 of the Texas Family Code. An assault bodily injury charge can become a domestic violence charge even if the assault is committed against  a former spouse, or someone you share a child with, or someone in the same household, whether or not a dating relationship exists. Even someone you used to live with can fall under the "family violence" definition in Texas. Houston domestic violence lawyer John "Casey" Keirnan has over 38 years of experience defending all types of domestic assault charges and family violence charges. Call 713-236-9700 for a free 24/7 consultation.

If you or someone you know is facing a family violence, domestic assault or domestic violence charge, consult an experienced Houston domestic assault defense attorney at (713) 236-9700 and learn how to successfully fight a domestic violence charge. Mercer and Keirnan is available 24/7 to answer your questions.

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Experienced Domestic Assault Attorney

(713) 236-9700

"Never been in trouble before and now I couldn't bond out of jail and had a court appointed lawyer who gave me little hope. I found defense attorney Casey Keirnan and Michael Mercer because of their experience as a theft defense lawyer. They replaced my court appointed attorney and everything changed."

by D. O. August 27, 2018

"I hired a top Houston drug lawyer with Mercer and Keirnan to defend my possession of a Controlled Substance Case. After a free consultation with Criminal defense attorney Michael Mercer, Mercer and Keirnan signed on to my case and after a few months my felony drug charge was dismissed!"

by RG One February 5, 2019

Misdemeanor Assault Definition

Under Texas Penal Code §22.01, a person commits a misdemeanor Assault offense if the person:

              (1) intentionally, knowingly or recklessly causes bodily injury to another;

              (2) intentionally or knowingly threatens another with imminent bodily injury; or

              (3) intentionally or knowingly causes physical contact with another when the

                  person knows or should reasonably believe that the other will regard the

                  contact as offensive or provocative.

The definition of Assault under paragraph (1) is classified as a Class A misdemeanor, punishable by up to a year in jail and/or a $4,000 fine. An assault under paragraphs (2) and (3) is considered a Class C Misdemeanor, punishable by a fine only, not to exceed $500.

The trouble with many assault cases is that the police usually don't arrive until after the incident occurs. The police officer can't possibly know the entire story, and too often the wrong person is arrested. Often only one side of the story is heard. As an experienced Houston assault attorney, John P. Keirnan will make sure that your voice isn't drowned out by your accusers.

Defenses to an Assault Charge

Section 9.31 of the Texas Penal Code establishes Self Defense as a defense to an assault charge or aggravated assault charge. When defending yourself, you may only use “reasonable force” and only when immediately necessary. Words alone are not enough to invoke the right to self defense. However, when taken in context with the person's actions, threatening words may warrant the use of self defense.

The defense of consent is also a defense to an assault charge, but may not be available for a felony assault with a deadly weapon charge. The term "mutual combat" is a common term used to show that both actors engaged each other and consented to the assault. Significant investigation is often required to successfully defend assault charges. Call an experienced Houston assault attorney at Mercer & Keirnan Criminal Attorneys for a free consultation.

Common Questions about Your Assault Case

Can the victim in an assault case drop the charges?

No. Only the district attorney can dismiss an assault case once charges have been filed. Before doing so, however, the district attorney will want to speak with the victim to obtain facts about the alleged assault and determine whether those facts are sufficient to prove that an assault occurred.

Can I get an assault charge off of my record?

If the case was dismissed, or if a jury found you not guilty, you are eligible to have the assault charge expunged from your record. You may also be eligible to petition the court for a non-disclosure, or "sealing", of the assault charge if you completed a deferred adjudication probation. Assault-family member charges are not eligible for a non-disclosure, even after a deferred adjudication. Assault-family member charges may only be expunged if the case was dismissed or resulted in a "not guilty" verdict. Hire an experienced assault attorney to give yourself the best chance of having any assault charge removed from your record.

What if I have witnesses to show I was falsely accused?

Many times in an assault case, the police fail to interview all the witnesses that saw what happened. These witnesses can often shed light on facts that are not in the original police report. If you have witnesses that you think can help your assault case, give their information to your assault defense attorney who can communicate this evidence to the district attorney. Never approach a district attorney or prosecutor by yourself without an attorney. The prosecutor is not there to help you exonerate yourself and may use anything you say against you should your case go to trial. Have your lawyer, preferably an experienced assault lawyer, interview these witnesses and obtain their statements.

Contact an Experienced Houston Assault Attorney

We provide our confidential consultation services free of charge to anyone facing charges of misdemeanor assault, felony assault, assault-family member, aggravated assault or any other misdemeanor or felony assault charge, contact experienced Houston assault attorney Casey Keirnan for a free evaluation.

Call 713-236-9700 for a free quote from an experienced Houston Assault Defense Attorney.

Do I Need a Lawyer for an Assault Charge?

Many people facing an assault charge ask the question, "Do I need a lawyer for an assault charge?" The answer is a resounding "Yes". In many cases, there is not enough evidence to prove that an assault occurred. The prosecuting attorney will go to great lengths to convince you that they have the evidence to obtain a guilty verdict. Without the knowledge and the reputation of an experienced assault lawyer, the accused in an assault case stands little chance against the prosecutor. Without a lawyer, the accused will not be taken seriously by either the judge or the prosecutor. A lawyer who is experienced in defending assault charges will know exactly what the prosecutor needs to prove their case against you and will expose the weaknesses of their case against you. With over 38 years of experience as assault defense attorneys, Mercer & Keirnan will make sure that you aren't found guilty of false accusations of assault.


"Lawyer of the Year"

Harris County Criminal Lawyers Association (2014)

Disclaimer: The information contained on this site is not intended as legal advice and is solely meant for general informational purposes. Any and all interaction with this site in no way creates an attorney-client relationship unless and until an agreement is actually reached.

Copyright 2018 Mercer & Keirnan. All Rights Reserved.

Why Hire Mercer & Keirnan

  • Over 38 Years of Criminal Defense Experience in Houston

  • 2014 Lawyer of the Year (Harris County Criminal Lawyers Association)

  • Recognized In the News nationwide as a renowned criminal defense attorney

  • We give our personal phone numbers to our clients so they can reach us easily any time

  • Avvo.com 2017 "Client's Choice"

  • Avvo.com rating of "Excellent"

Request a phone call directly from Mr. Keirnan and Mr. Mercer to talk about your case.

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Mercer & Keirnan

Houston Criminal Defense Attorneys

917 Franklin St #550

Houston, Texas 77002




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 In addition to Harris County, we also serve:

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  • Officer's Murder Trial Begins with Emotion, ABC7 News Chicago - Mar. 18, 2010