top of page

Tell Us About Your Case

"Lawyer of the Year"

Harris County Criminal Lawyers Association (2014)

Houston Marijuana Lawyer

Houston Marijuana Lawyer With 38 Years of Experience

Houston marijuana lawyer John Keirnan has 38 years of experience defending marijuana charges and other drug possession charges. Possession of marijuana cases represent a large portion of the criminal defense areas that Mercer & Keirnan practice. A common defense to possession of marijuana occurs when an officer conducts a search without consent or probable cause and unlawfully seizes the marijuana. At Mercer & Keirnan, we fight hard to protect your right to privacy. Call now for a free consultation and speak with an experienced Houston marijuana lawyer today.

Free 24/7 Consultations

Experienced Houston Marijuana Attorney

(713) 236-9700

Houston Marijuana Lawyer

Were You the Victim of an Illegal Search?

Contact a Marijuana Attorney Today to Find Out

If you or someone you know has been charged with possession of marijuana, contact a Houston marijuana lawyer today at 713-236-9700 for a free 24/7 consultation. An attorney experienced in fighting marijuana/weed possession charges will uncover any potential defenses in your case, maximizing the chances of beating the charges against you.

Free 24/7 Consultations

Experienced Houston Marijuana Attorneys / Possession Lawyers

(713) 236-9700

Client Reviews


Average Rating: 5 out of 5 (11 reviews)

Definition of 'Marijuana' and 'Possession'

"Marijuana" is defined as any Cannabis sativa plant, growing or not, including seeds or preparation of marijuana, or a package with marijuana traces. There must be a "usable" amount of marijuana. Thus, stems do not fall under the definition of marijuana. A court may order an officer to re-weigh the marijuana, which could reduce a felony charge to a misdemeanor. Request a free consultation with a marijuana attorney today by calling 713-236-9700. 

"Possession" means care, custody or control with actual knowledge of possession. A common defense to possession of marijuana is lack of actual knowledge. If you didn't know you possessed the marijuana, you are not guilty of marijuana possession. To discover the defenses in your case, call an experienced marijuana lawyer at (713) 236-9700 for a free consultation.


"Michael Mercer and Casey Keirnan are some of the best criminal defense attorneys in Houston. I was facing an aggravated assault with a deadly weapon charge in Harris County and they got this felony assault case dismissed outright with no probation. Anyone charged with assault or aggravated assault in Houston should strongly consider calling Mercer and Keirnan Criminal Defense Attorneys. I couldn’t be happier with how they handled my case!"

by H. I. March 8, 2024


"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

Criminal Penalties for Marijuana Possession in Texas

Weight          Classification             Max Penalty

<2 ounces    Class B Misdemeanor  6 months

4 ozs-5 lbs   State Jail Felony         6 months-2 years

5-50 lbs         3rd Degree Felony      2-10 years


"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

50-2,000 lbs   2nd Degree Felony     2 -20 years

Over 2,000lbs  1st Degree Felony     5-99 years or life

Penalties for Manufacture or delivery of marijuana are listed under Section 481.120 of the Texas Health and Safety Code, When imposing punishment for marijuana possession, the court takes into consideration your criminal background and the amount of marijuana found. Any misdemeanor marijuana or felony marijuana conviction will cause the suspension of your Texas driver's license. Anyone facing marijuana charges should contact an experienced Houston marijuana lawyer immediately. Call (713) 208-7682 for a free evaluation.

Smoking marijuana and then getting behind the wheel of a car could also lead to a DWI arrest depending on your level of intoxication, even if you haven't had a drop of alcohol. The state's ability to prove a DWI arrest involving marijuana depends on whether the driver has smoked synthetic marijuana like Kush or K-2 or the actual marijuana plant or a THC Vape pen.


"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

DWI Arrests Involving Marijuana, THC Vape Pens and Synthetic Marijuana

DWI arrests involving marijuana, THC vape pens and synthetic marijuana are common in Texas. Smoking marijuana and then getting behind the wheel of a car could also lead to a DWI arrest depending on your level of intoxication, even if you haven't had a drop of alcohol. The state's ability to prove a DWI arrest involving marijuana depends on whether the driver has smoked synthetic marijuana like Kush or K-2 or the actual marijuana plant or a THC Vape pen.

houston marijuana defense lawyer

Hire an Experienced Houston Marijuana Defense Attorney

An experienced marijuana defense attorney at Mercer & Keirnan is standing by 24/7 to evaluate your marijuana possession case and give you a free quote. With over 40 years of combined experience defending misdemeanor and felony possession of marijuana charges, attorneys John Keirnan and Michael Mercer have the wisdom and skills necessary to successfully defend your marijuana case. When it comes to fighting your possession of marijuana charge, don't gamble with your future. Make the sure bet, and hire an experienced drug lawyer today.

Free 24/7 Consultations

Call 713-236-9700 or Request a Free Quote Online

Experienced Houston Marijuana Lawyer

Do I Need a Drug Lawyer to Fight My Possession of Marijuana Charge?

Many people facing a possession of marijuana charge ask the question, "Do I need a drug lawyer to fight my marijuana charge?" The answer is Yes. In many marijuana cases, there may not be enough evidence to prove the case. The arresting officer may have violated your constitutional rights during his search for the marijuana, especially if the search was conducted without a warrant or without probable cause. Without the knowledge and the reputation of an experienced marijuana defense lawyer, the accused in a possession of marijuana case stands little chance against the prosecutor. Without representation, you will not be taken seriously by either the judge  or the prosecutor.

An experienced marijuana defense lawyer will know exactly what the prosecutor needs to prove their case against you and will expose the weaknesses of their case. With over 38 years of experience as a Possession of Marijuana Lawyers, John P. Keirnan and Michael D. Mercer will help you to achieve the best possible result in your case.

bottom of page