IN THE UNITED STATES DISTRICT COURT

FOR THE EASTERN DISTRICT OF TEXAS

SHERMAN DIVISION

BLAKE J. WATTERSON;

Plaintiff,

v.

BUREAU OF ALCOHOL, TOBACCO, 

FIREARMS AND EXPLOSIVES; 

STEVEN DETTELBACH, in his 

official capacity as Director of the 

Bureau of Alcohol, Tobacco, Firearms 

and Explosives; 

UNITED STATES DEPARTMENT 

OF JUSTICE; 

MERRICK GARLAND, in his official 

capacity as Attorney General of the 

United States; and

UNITED STATES OF AMERICA,

Defendants.

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Civil Action No. 4:23-cv-00080

PLAINTIFF’S NOTICE OF SUPPLEMENTAL AUTHORITY

Plaintiff Watterson files this notice of supplemental authority in support of his 

Motion for Relief under 5 U.S.C. § 705 or, Alternatively, for a Preliminary Injunction, 

ECF No. 7 (“§ 705 Motion”), and his Motion for Summary Judgment, ECF No. 6.

Today, the Fifth Circuit issued its decision in Mock v. Garland regarding the same 

rule that Watterson challenges, ATF, Factoring Criteria for Firearms with Attached 

“Stabilizing Braces,” 88 Fed. Reg. 6,478 (Jan. 31, 2023) (the “Rule”). See Ex. 1. As 

explained below, the Mock decision supports Watterson’s arguments, but it ends this 

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Court’s preliminary injunction and does not provide any relief to Watterson.

Watterson therefore respectfully renews his request that this Court grant his § 705 

Motion, schedule a hearing on his summary-judgment motion, and issue a decision 

on the merits expeditiously.

On Jan. 31, 2023, Watterson filed this suit and a summary-judgment motion. 

See Compl, ECF No. 1 (Jan. 31, 2023); Mot. for Summ. J., ECF No. 6 (Jan. 31, 2023). 

Shortly thereafter, Watterson filed the § 705 Motion and requested expedited 

consideration. See § 705 Mot., ECF No. 7 (Feb. 2, 2023); Emerg. Mot. for Expedited

Consideration, ECF No. 8 (Feb. 7, 2023). That motion for expedited consideration was

partially granted, and this Court stated that it would “issue an order” on Watterson’s

§ 705 Motion “on or before March 24, 2023.” Order, ECF No. 18 (Feb. 9, 2023), at 3.

On May 23, 2023, before this Court ruled on the § 705 Motion or summaryjudgment motion, the Fifth Circuit preliminarily enjoined the enforcement of the Rule

against the Mock plaintiffs pending appeal. See Pl.’s Notice of Supp. Authority, Ex. 1, 

ECF No. 33-1 (May 23, 2023). In light of that ruling, this Court granted Watterson a 

preliminary injunction “pending resolution of the Fifth Circuit’s decision in Mock v. 

Garland.” Order, ECF No. 37 (June 7, 2023) (the “June 7th Order”), at 2. This Court 

also ordered briefing “addressing whether the Court should stay this action until the 

Fifth Circuit’s decision.” Id. at 3. Watterson explained that staying the case was 

unwarranted, that the summary-judgment motion was “ripe for resolution,” and that 

deciding this case on the merits “quickly would promote judicial efficiency, conserve 

resources, and serve the public interest.” Br. Opposing Stay, ECF No. 38 (June 21, 

2023), at 1. Watterson also detailed how he continued to suffer daily irreparable 

harm, even with the preliminary injunction in place, because the Court did not “stay 

the Rule or enjoin the Department from enforcing the statutes in accordance with the

Department’s erroneous interpretation of those statutes.” Id. at 9. This Court did not 

stay the case pending the resolution of the Mock appeal.

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Today’s Mock decision necessitates immediate relief for Watterson and further 

demonstrates that Watterson is entitled to his requested preliminary relief and to 

summary judgment. First, the decision has exacerbated Watterson’s need for relief. 

In Mock, the Fifth Circuit concluded that the Mock plaintiffs are likely to succeed on 

the merits and reversed the district court’s contrary conclusion. See Ex. 1 at 23, 38. 

The Fifth Circuit, however, did not consider the other preliminary-injunction factors 

or issue a nationwide injunction. Id. at 38. Instead, it maintained its limited 

preliminary injunction for the Mock plaintiffs1 and remanded the case to the district 

court to assess the remaining preliminary-injunction factors in the first instance. See 

id. at 38-40. The Fifth Circuit’s decision accordingly does not provide any relief to 

Watterson. What is more, this Court’s preliminary injunction has ended because the 

Court tied its duration to the resolution of the Mock appeal. See June 7th Order at 2. 

Watterson is therefore suffering irreparable harm that calls for immediate relief. See 

§ 705 Mot. at 10-11; § 705 Reply, ECF No. 25 (Feb. 27, 2023), at 1-2, 5; Br. Opposing 

Stay at 8-11.

Second, Mock supports Watterson’s arguments in the § 705 Motion and 

summary-judgment motion. In Mock, the Fifth Circuit concluded that the Mock 

plaintiffs were likely to succeed on their claim that the Rule violates the procedural 

and substantive requirements of the Administrative Procedure Act. See Ex. 1 at 23. 

Although Watterson did not assert that same claim, the Fifth Circuit nonetheless 

provided important guidance in reaching that conclusion. For starters, the Fifth 

Circuit confirmed that the Rule “is a legislative rule,” id. at 23-31, as Watterson 

argued, Mot. for Summ. J. at 8-9, 25-29; § 705 Mot. 14-15, § 705 Reply at 3-4, and the 

1 The limited injunctive relief also applies to individual Mock plaintiffs’ “resident 

family members” and to “the customers and members whose interests Plaintiffs 

Maxim Defense and Firearms Policy Coalition (“FPC”) have represented since day 

one of this litigation.” See Notice of Suppl. Auth., Ex. 1, ECF No. 36-1 (June 2, 2023), 

at 2.

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Department has wrongly disputed, § 705 Opp., ECF No. 23 (Feb. 23, 2023), at 36-37, 

44-45. In addition, the Fifth Circuit recognized the burdensome nature of the 

statutory restrictions that the Rule extends to pistols with stabilizing braces. See Ex. 

1 at 2, 6-7, 9; see also Mot. for Summ. J. at 2-5, 7-8, 14-15; § 705 Mot. at 1-2, 5, 10-11; 

§ 705 Reply at 1-3. The Mock decision thus belies the Department’s attempt to portray 

the Rule’s burdens as too modest to implicate Second Amendment rights. See § 705 

Opp. at 25-27; § 705 Surreply, ECF No. 27 (Mar. 3, 2023), at 3. Finally, the Mock 

concurrence rightly “suspect[s] that the Final Rule would likely fail constitutional 

muster” and criticizes the Department for failing to “identif[y] any historical tradition 

of requiring ordinary citizens to endure a lengthy, costly, and discretionary approval

process just to use accessories that make an otherwise lawful weapon safer.” See Ex. 

1 at 41 (Willett, J., concurring). 

Therefore, the recent Mock decision provides further support for Watterson’s 

arguments that the Rule is unconstitutional and exceeds the Department’s statutory 

authority. Watterson respectfully requests that the Court grant his § 705 Motion and 

summary-judgment motion as soon as possible to prevent additional irreparable 

harm.

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Date: August 1, 2023 Respectfully submitted,

/s/Autumn Hamit Patterson

ROBERT HENNEKE

Texas Bar No. 24046058

rhenneke@texaspolicy.com

CHANCE WELDON

Texas Bar No. 24076767

cweldon@texaspolicy.com

AUTUMN HAMIT PATTERSON

Texas Bar No. 24092947

apatterson@texaspolicy.com

CLAYTON WAY CALVIN

Texas Bar No. 24132780

ccalvin@texaspolicy.com

TEXAS PUBLIC POLICY FOUNDATION

901 Congress Avenue

Austin, Texas 78701

Telephone: (512) 472-2700

Facsimile: (512) 472-2728

Counsel for Plaintiff

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CERTIFICATE OF SERVICE

I certify that on August 1, 2023, I electronically filed the foregoing document 

with the Clerk of the Court using this Court’s CM/EMF system, which will notify all 

counsel of record of such filing.

/s/Autumn Hamit Patterson

AUTUMN HAMIT PATTERSON

Case 4:23-cv-00080-ALM Document 40 Filed 08/01/23 Page 6 of 6 PageID #: 802