Tex. Code of Criminal Procedure § 19A.153

(a) A challenge to a grand juror may be made orally for any of the following causes:

(1) that the grand juror is insane;

(2) that the grand juror has a defect in the organs of feeling or hearing, or a bodily or mental defect or disease that renders the grand juror unfit for grand jury service, or that the grand juror is legally blind and the court in its discretion is not satisfied that the grand juror is fit for grand jury service in that particular case;

(3) that the grand juror is a witness in or a target of an investigation of a grand jury;

(4) that the grand juror served on a petit jury in a former trial of the same alleged conduct or offense that the grand jury is investigating;

(5) that the grand juror has a bias or prejudice in favor of or against the person accused or suspected of committing an offense that the grand jury is investigating;

(6) that from hearsay, or otherwise, there is established in the mind of the grand juror a conclusion as to the guilt or innocence of the person accused or suspected of committing an offense that the grand jury is investigating that would influence the grand juror's vote on the presentment of an indictment;

(7) that the grand juror is related within the third degree by consanguinity or affinity, as determined under Chapter 573, Government Code, to a person accused or suspected of committing an offense that the grand jury is investigating or to a person who is a victim of an offense that the grand jury is investigating;

(8) that the grand juror has a bias or prejudice against any phase of the law on which the state is entitled to rely for an indictment;

(9) that the grand juror is not a qualified grand juror; or

(10) that the grand juror is the prosecutor on an accusation against the person making the challenge.

(b) A challenge under Subsection (a)(3) may be made ex parte. The court shall review and rule on the challenge in an in camera proceeding. The court shall seal any record of the challenge.

(c) In this article, "legally blind" has the meaning assigned by Article 35.16(a).