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"Lawyer of the Year"

Harris County Criminal Lawyers Association (2014)

Houston Criminal Defense Attorneys Mercer & Keirnan

Looking for an Experienced  Criminal Defense Attorney in Houston?

Mercer and Keirnan

Are you or a loved one looking for an experienced criminal lawyer in Houston? With over 40 years of experience, Mercer & Keirnan Criminal Defense Attorneys is a wise choice to help you fight your misdemeanor or felony charge.


The decisions you make early on in the case are critical to achieving a favorable outcome. Call 713-236-9700 for a free evaluation and speak directly with experienced Houston attorneys John P. "Casey" Keirnan and Michael Mercer.

Top Assault Attorneys in Houston

Criminal defense attorneys Casey Keirnan and Michael Mercer of Mercer & Keirnan are some of the top assault attorneys in Houston. For over 40 years, Casey Keirnan has successfully represented people charged with assault and aggravated assault, assault on a family member, domestic violence and all other assault charges. People hire Mercer & Keirnan because we are highly successful in getting assault charges dropped and dismissed. Come in or call 713-236-9700 for a free consultation and let Mercer & Keirnan assault attorneys show you how we will defend your assault case.

Types of Assault Charges

Houston Criminal Defense Attorney John P. Keirnan

Experienced Houston Drug Charge Lawyers

Arrested for drug possession? Mercer & Keirnan are experienced Houston drug charge lawyers that have provided experienced criminal defense for drug charges in Houston for over 40 years. The 4th Amendment protects your right to be free from unreasonable searches and seizures. Your right to privacy extends not only to your person and home, but also to your vehicle. Remember that you have the right to refuse an officer's search of your vehicle. If your constitutional rights were violated as a result of an illegal search, call a Houston drug lawyer at Mercer & Keirnan today.

Types of Drug Charges

Houston DWI attorney John P. "Casey" Keirnan has fought DWI/DUI charges  in Houston for over 40 years. Mr. Keirnan has considerable trial experience in the field of criminal defense, particularly defending DWI charges. Don't let police or prosecutors intimidate you into giving up your right to a trial by jury. Protect your rights and hire a Houston DWI attorney from Mercer & Keirnan who won't back down from a fight. Contact us for a free evaluation and discover potential defense strategies for your DWI case. 

Mercer & Keirnan - Harris County Criminal Defense Attorneys

Harris County Criminal Defense Attorneys John "Casey" Keirnan and Michael Mercer of Mercer & Keirnan defend people charged with any and all misdemeanor or felony criminal charge. In 2014, Mr. Keirnan was awarded "Lawyer of the Year" by his colleagues in the Harris County Criminal Lawyers Association for the incredible results he achieved defending his clients. In 2010, the Harris County Criminal Lawyers Association awarded Mr. Keirnan the "Unsung Hero's Award" after Mr. Keirnan became the first attorney in Texas to successfully argue a motion to declare the Texas death penalty statute unconstitutional.


Attorneys in and around Harris County agree that John "Casey" Keirnan is one of the best criminal defense attorneys in Texas. Anyone who is arrested or charged with a crime in Houston can speak with Mr. Keirnan or Mr. Mercer directly about their misdemeanor or felony charge by calling 713-236-9700 24 hours a day, 7 days a week.

Over 38 Years of Experience

Defense attorney Casey Keirnan has four decades of experience in criminal defense, including:

Harris County Criminal Defense Lawyer

Harris County Lawyer of the Year

Attorney John P. "Casey" Keirnan was awarded Lawyer of the Year in 2014 by his colleagues in the Harris County Criminal Lawyers Association

Mercer & Keirnan Criminal Defense Lawyers

Law Offices of Mercer & Keirnan

Browse our "In the News" section and discover the nationally renowned criminal defense attorneys at Mercer & Keirnan.

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