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Michael D. Mercer

Houston Criminal Defense Lawyer

Mercer & Keirnan

917 Franklin St #550

Houston, TX 77002

P: (713) 236-9700

F: (713) 236-1802


Houston criminal defense attorney Michael D. Mercer worked for the Harris County District Attorney's office for one year before founding the criminal defense law firm of Mercer & Keirnan in 2012. Unlike other attorneys who practice multiple areas of law, Mr. Mercer devotes 100% of his practice to criminal defense, taking on clients charged with all misdemeanor and felony offenses.

Practice Areas

Houston Criminal Defense Lawyer Michael Mercer
  • Assault

  • Assault-Family Member & Domestic Violence

  • Aggravated Assault

  • Drug Charges


  • Expunction/Expungement

  • Money Laundering

  • Marijuana Possession

  • Online Solicitation of a Minor

  • Prostitution

  • Sexual Assault and other Sex Crimes

  • Shoplifting

  • Theft

  • Weapons Charges

Since 2012, Michael has handled more than 500 criminal cases in and around Harris County. More than 100 of those cases involved assault charges, aggravated assault charges and domestic violence charges. More than half of those cases resulted in either dismissal (without probation) or not guilty verdicts.

Click a banner to read reviews from prior clients

Michael commands an impressive knowledge of the law and is an exceptional negotiator in the courtroom, as indicated by numerous former clients in online reviews and testimonials of Mercer & Keirnan. When Michael signs on to a case, he devotes himself fully to making sure his client gets the best possible result. Whether issuing subpoenas for hidden evidence, taking to the street to find and interview witnesses, or undergoing hours of research on the law, Attorney Michael Mercer goes above and beyond the duty he owes to his clients. His tireless work ethic and professionalism are propelling him to become one of the brightest and hard-nosed criminal defense lawyers at the courthouse.

MEMBER: Harris County Criminal Lawyers Association, Texas Criminal Defense Lawyers Association, Houston Young Lawyers Association

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


"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

"Lawyer of the Year"

Harris County Criminal Lawyers Association (2014)

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