Atty. Mark Janssen

Atty. Mark Janssen

Mr. Mark Janssen is a lawyer practicing criminal trial law, family law, civil litigation and 1 other area of law.

San Marcos San Marcos 44 yrs experience 44 year
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Civil Litigation & More Attorney · Serving San Marcos, TX · 44+ Years Experience

Profile Summary

About Mark Janssen at a Glance

Mark Janssen is a criminal defense, family law, and litigation attorney based in San Marcos, Texas. They have 44+ years of legal experience, licensed to practice since 1982. Admitted to practice in Texas (1982) and Colorado (1990). Educated at Texas Tech University (J.D., 1982) and Texas A. & M. University (B.A., 1979). Recognitions include CV Notable. Serves clients in San Marcos, TX and the surrounding metropolitan area.

Verified attorney profile · Updated October 2026

About Mark Janssen

  • Mr. Mark Janssen is a lawyer practicing criminal trial law, family law, civil litigation and 1 other area of law
  • Mark received a B.A. degree from Texas A. & M. University in 1979, and has been licensed for 44 years
  • Mark practices in San Marcos, TX

Practice Areas Explained

Mark Janssen's Areas of Legal Practice

Each practice area below reflects the types of cases Mark Janssen handles, with a practical overview of what that area of law involves and how it may apply to your situation in San Marcos.

Criminal Defense in San Marcos

A criminal defense attorney protects your rights from arrest through trial. Find experienced lawyers handling DUI, drug, federal, theft, and violent-crime charges.

Mark Janssen is one of 212,605 criminal defense attorneys indexed nationally. Browse criminal defense attorneys in Texas →

Family Law in San Marcos

Family law attorneys handle divorce, child custody, child support, adoption, prenups, and protective orders. Find verified family lawyers near you.

Mark Janssen is one of 185,688 family law attorneys indexed nationally. Browse family law attorneys in Texas →

Civil Litigation in San Marcos

Civil litigation attorneys for breach of contract, business disputes, civil rights, and class action lawsuits.

Mark Janssen is one of 450,751 litigation attorneys indexed nationally. Browse litigation attorneys in Texas →

Jurisdictional Context

Why Local Counsel Matters in San Marcos

Practicing law in Texas. Legal matters in Texas are governed by state-specific rules of civil and criminal procedure, statutes of limitations, and substantive law. Cases originating in San Marcos are typically filed in the local municipal court or the appropriate Texas state district court, depending on subject matter and amount in controversy. An attorney licensed in Texas brings working knowledge of local procedural deadlines, judicial practices in this venue, and the substantive law that applies to cases brought here. Out-of-state attorneys generally cannot represent clients in Texas courts without local counsel or pro hac vice admission.

San Marcos Courts and Legal Process

Choosing a San Marcos-based attorney means your counsel already knows the local docketing timelines, preferred filing formats, and how individual judges typically rule on procedural motions — details that only come from practicing in this jurisdiction day after day. That local familiarity can translate to better strategy, faster filings, and fewer costly surprises.

Looking for additional Texas attorneys? Browse all attorneys in San Marcos or all attorneys in Texas.

Frequently Asked

Common Questions About Mark Janssen

Where is Mark Janssen's law office located?
Mark Janssen's law practice is located in San Marcos, Texas. You can contact the office directly through this profile page.
What practice areas does Mark Janssen handle?
Mark Janssen focuses on criminal defense, family law, litigation. Each practice area listed reflects experience handling cases of that type in Texas.
How long has Mark Janssen practiced law?
Mark Janssen has 44+ years of legal experience and has been licensed since 1982.
Where did Mark Janssen go to law school?
Mark Janssen earned their education at (J.D., 1982); (B.A., 1979).
How can I contact Mark Janssen for a consultation?
You can contact Mark Janssen directly through this profile page. Click "Ask the Attorney" to submit a question, or "Schedule a Consultation" to book a meeting. Most claimed-profile attorneys respond within one business day.
What awards or recognition has Mark Janssen received?
Mark Janssen's notable recognition includes: CV Notable.

Professional Profile

Why Clients in San Marcos Choose Mark Janssen

Selecting an attorney is one of the most consequential decisions you can make when a legal matter arises. Below are the core qualities that distinguish Mark Janssen's practice in the field of criminal defense, family law, and litigation.

Decade-Tested Legal Experience

Mark Janssen brings 44+ years of hands-on legal practice — enough to have navigated the recurring fact patterns, procedural traps, and negotiation dynamics that shape case outcomes.

Multi-State Bar Admission

Licensed in Texas and Colorado, Mark Janssen can represent clients in cases that span state lines or require counsel in multiple jurisdictions.

Broad Practice Area Coverage

Covering criminal defense, family law, and litigation, Mark Janssen can address the full spectrum of a client's legal needs without requiring referrals to separate specialists for each issue.

Local Presence in San Marcos

A San Marcos-based practice means Mark Janssen attends hearings in the same courthouses, knows the local clerks, and understands the unwritten scheduling norms that affect every case filed here.

Case Types

Common Legal Issues Mark Janssen Handles in San Marcos

Below is a representative sample of the types of matters Mark Janssen has experience with under Texas law. If your situation involves one of these case categories, this attorney may be well positioned to help you understand your options.

Divorce and property division
Family Law
Child custody and support
Family Law
Spousal support (alimony)
Family Law
Prenuptial agreements
Family Law

This list is illustrative, not exhaustive. Contact Mark Janssen directly to discuss the specifics of your situation.

Search Reference

How People Find Mark Janssen Online

Prospective clients searching for legal help in San Marcos commonly use a combination of the attorney's name and their specific legal need. The following search terms frequently lead people to this profile and to attorneys like Mark Janssen.

Mark Janssen attorney Mark Janssen lawyer Mark Janssen San Marcos Mark Janssen Texas Mark Janssen reviews Mark Janssen contact criminal defense attorney in San Marcos criminal defense lawyer San Marcos best criminal defense attorney San Marcos top rated criminal defense lawyer near me criminal defense attorney Texas find a lawyer near me how to hire an attorney

If any of the above matches what you searched for, you've found the right profile. Use the contact options at the top of this page to get in touch with Mark Janssen directly.

Mark Janssen's Practice Areas & Specializations

Education & Law School Background

J.D.
Texas Tech University
- 1982
B.A.
Texas A. & M. University
- 1979

Awards & Professional Honors

CV Notable

Bar Admissions & Licensed Jurisdictions

Texas
Admitted: 1982
Colorado
Admitted: 1990

Client Reviews & Ratings — Mark Janssen

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