Imagine you are days away from a custody modification trial. Then the court allows the other side to take a deposition after the discovery deadline has passed. Can you ask a higher court to step in before the trial starts?
Per the published opinion, a September 2026 decision from the Thirteenth Court of Appeals answers that question, and the answer is “rarely.” In In re J.D.O., No. 13-26-00660-CV, 2026 WL 2870905 (Tex. App.—Corpus Christi–Edinburg Sept. 23, 2026, orig. proceeding) (mem. op.), a parent asked the court to stop a jury trial over a late deposition. The court refused.
The case comes out of Nueces County, but the rules it applies are statewide. They govern custody disputes in Dallas County courtrooms every day. As a Dallas divorce attorney with more than 25 years in family court, I see parents misjudge these rules often, and the misjudgment can be costly.
This article covers three questions:
- What a petition for writ of mandamus is, and why it is so hard to win
- How Texas Family Code § 156.101 controls custody modification
- What parents should do when a pretrial ruling seems unfair
Case Background: A Decade-Long Custody Dispute Reaches the Eve of Trial
Who Were the Parties?
The parent who filed the petition, J.D.O., represented herself (pro se). The underlying case began in 2014 in the 319th District Court of Nueces County. The Thirteenth Court of Appeals noted that it had already handled at least four earlier appeals and original proceedings from the same case, dating back to 2017.
That history matters. Many custody cases do not end with the first decree. They come back as modification suits when circumstances change, sometimes several times over a child’s life.
What Was the Dispute?
The trial court set a jury trial on a modification of conservatorship for September 28, 2026. Before trial, the court authorized a deposition after the discovery deadline had passed and shortly before trial.
J.D.O. filed a petition for writ of mandamus. She argued the trial court abused its discretion by:
- Allowing the deposition after the discovery deadline, close to trial
- Treating the deposition as supplying, or conclusively establishing, the statutory grounds for permanent modification under Texas Family Code § 156.101
She also filed an emergency motion for temporary relief under Texas Rule of Appellate Procedure 52.10. She asked the court to keep certain evidence out of the trial and to prevent the use of specific jury instructions.
What Did the Court Decide?
On September 23, 2026, five days before trial, the court denied both the petition and the emergency motion. Its per curiam memorandum opinion stated that the relator “has not met her burden to obtain relief.”
The court did not explain which part of the test she failed. Under Rule 52.8(d), an appellate court that denies mandamus relief is not required to write an opinion at all.
Legal Analysis: Why Mandamus Relief Is So Difficult to Obtain
What Is a Writ of Mandamus in a Texas Family Case?
A writ of mandamus is an order from an appellate court directing a trial judge to do, or undo, something. It allows review before the case is over, without waiting for a final judgment and a regular appeal.
The court described it as “an extraordinary remedy that is available in limited circumstances to correct clear errors in exceptional cases,” quoting In re R., 728 S.W.3d 717, 719 (Tex. 2026). Few remedies in Texas law face a higher bar.
The Two-Part Test Every Relator Must Meet
Under W. v. P., 827 S.W.2d 833 (Tex. 1992), and In re P.I.C.A., 148 S.W.3d 124 (Tex. 2004), the party seeking mandamus (the “relator”) must prove two things:
- A clear abuse of discretion. A trial court abuses its discretion when its rulings are “arbitrary, unreasonable, or made without reference to guiding legal principles.” In re S.F.M.A.I., 712 S.W.3d 53, 59 (Tex. 2025).
- No adequate remedy by appeal. Courts weigh this through a “benefits-and-detriments analysis.” In re A.C.L.P., 655 S.W.3d 837, 843 (Tex. 2022).
The burden sits entirely on the relator. In re H.E.B.G.C., 492 S.W.3d 300, 302 (Tex. 2016). The relator must also supply a proper record and appendix under Rules 52.3 and 52.7.
Do Self-Represented Parents Get More Leeway?
No. The court cited B. v. S., 832 S.W.2d 424, 426 (Tex. App.—Houston [1st Dist.] 1992): “Even a pro se applicant for a writ of mandamus must show himself entitled to the extraordinary relief he seeks.”
Texas courts hold self-represented litigants to the same procedural rules as lawyers. Custody stakes are high, and the procedural requirements do not bend.
A Dallas family law attorney who handles original proceedings knows how much of the outcome depends on the record. A petition without certified copies of the challenged order and the relevant hearing transcripts can fail before the court ever reaches the merits.
How Does Texas Family Code § 156.101 Work?
Section 156.101 sets the grounds for modifying custody (conservatorship) or possession and access. A court may modify an order if doing so is in the child’s best interest and:
- The circumstances of the child, a conservator, or another affected party have materially and substantially changed since the earlier of the date the prior order was rendered or the date a mediated or collaborative settlement agreement was signed
- A child at least 12 years old has expressed a preference to the court about who should have the exclusive right to designate the child’s primary residence; or
- The conservator with that right has voluntarily given up primary care and possession of the child for at least six months
J.D.O. argued the deposition was being treated as proof of one of these predicates. The appellate court did not reach whether that was true. It ruled only that she had not carried her burden in a mandamus proceeding.
Why Pretrial Evidence Disputes Usually Wait for Appeal
The opinion does not say why the request failed. However, the general framework suggests why such petitions face long odds. Trial courts have broad discretion over discovery deadlines and scheduling, and Texas Rule of Civil Procedure 190.5 permits courts to modify a discovery period.
Rulings on admitting evidence and on jury instructions can generally be raised in a regular appeal after trial. When an ordinary appeal is available, the second prong of the mandamus test is hard to meet.
Jury trials also have defined limits in custody cases. Under Texas Family Code § 105.002, a jury may decide who is appointed managing conservator and who designates the child’s primary residence. It may not decide child support or the specific terms of possession and access, which remain with the judge.
What Is the Precedential Impact?
This is an unpublished memorandum opinion, so its precedential weight is limited. Its value lies in showing how consistently Texas appellate courts apply the W. and P. standard.
For Dallas parents, the practical message is plain. Appellate courts will not usually rescue a party from a pretrial ruling days before a custody trial. The trial level is where most of the battle is won or lost.
Dallas County cases follow the same standard. Mandamus petitions from Dallas family courts go to the Fifth District Court of Appeals, which applies the same W. and P. test. Any Dallas divorce attorney weighing a mandamus petition starts with the same honest question: can this ruling really not be fixed on appeal?
Key Takeaways for Dallas Divorcing and Divorced Parents
- Custody orders can change. A material and substantial change in circumstances can reopen conservatorship years after the decree.
- Mandamus is a narrow exception. Expect the trial court’s pretrial rulings to stand through trial in most cases.
- Preserve your objections. If you plan to challenge a ruling on appeal, you must object properly on the record at trial.
- Self-representation carries real risk. Courts apply the same rules to everyone.
A Dallas child custody lawyer can help you build a record that protects your options.
Strategic Insights: What We’ve Learned From This Case
When a late deposition appears shortly before trial, different strategies might include a motion for continuance, a motion to exclude or limit the testimony, a request for a limiting instruction, or proposed jury questions that track § 156.101’s elements precisely. Each keeps the issue alive for a regular appeal. Mandamus remains available, but it works best as a targeted tool backed by a complete record, not as a substitute for trial-level objections.
Frequently Asked Questions
Can I appeal a judge’s ruling before my custody trial?
Usually not. Most rulings are reviewed after a final judgment. Mandamus is an exception reserved for clear abuses of discretion where an ordinary appeal is inadequate.
What counts as a “material and substantial change” in Texas?
Common examples include a parent’s relocation, remarriage, changes in a child’s needs, or a change in a parent’s ability to care for the child. Each case turns on its own facts.
Does a custody modification affect child support?
It can. A change in the child’s primary residence often leads to a new support calculation, so speak with a Dallas child support lawyer about both issues together.
Talk to a Dallas Divorce Attorney Who Gives You Straight Answers
If you are facing a custody modification, a divorce, or a disputed pretrial ruling, you need honest guidance early. At the Law Office of Michael P. Granata, we offer more than 25 years of Dallas family law experience, strategic planning balanced with compassion, and transparent communication about realistic outcomes.
Our Dallas divorce attorney team represents clients throughout Dallas County, including Irving, Richardson, Garland, Mesquite, DeSoto, Grand Prairie, Lakewood, Highland Park, Cockrell Hill, Lancaster, Seagoville, and Duncanville. If you have been searching for a “divorce attorney near me,” schedule a Dallas divorce lawyer consultation today. Call (214) 977-9050, or explore more case analyses on our blog.
