Filed 1/14/21 Villanueva v. Becerra CA5

NOT TO BE PUBLISHED IN THE OFFICIAL REPORTS

California Rules of Court, rule 8.1115(a), prohibits courts and parties from citing or relying on opinions not certified for 

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or ordered published for purposes of rule 8.1115.

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIFTH APPELLATE DISTRICT

DANNY VILLANUEVA et al.,

Plaintiffs and Appellants,

v.

XAVIER BECERRA, as Attorney General, etc. 

et al.,

Defendants and Respondents.

F078062

(Super. Ct. No. 17CECG03093)

OPINION

APPEAL from a judgment of the Superior Court of Fresno County. Mark W. 

Snauffer, Judge.

Michel & Associates, C.D. Michel, Anna M. Barvir, and Sean A. Brady, for 

Plaintiffs and Appellants. 

Xavier Becerra, Attorney General, Thomas S. Patterson, Senior Assistant Attorney 

General, Paul Stein and P. Patty Li, Deputy Attorneys General, for Defendants and 

Respondents. 

-ooOoo-
2

In 2016, the California Legislature closed a loophole in the Roberti-Roos Assault 

Weapons Control Act (Pen. Code,1 §§ 30500, et seq., AWCA) by revising the statutory 

definition of assault weapons to include a class of weapons that were previously outside 

of AWCA’s coverage, commonly known as “bullet-button” assault weapons.2 (Sen. Bill 

No. 880 (2015-2016 Reg. Sess.) (Senate Bill 880); Stats. 2016, ch. 48, § 1, amending 

§§ 30515, 30900, adding 30680, eff. Jan. 1, 2017.)

3 Under the revised law, those who 

lawfully owned bullet-button assault weapons before the effective date of the statutory 

revision (i.e., Jan. 1, 2017) could keep them, subject to a requirement that all such 

weapons had to be registered by July 1, 2018.4(§§ 30900, subd. (b); 30680.) 

Additionally, and important to the present appeal, the California Department of Justice 

(DOJ) was directed to adopt regulations to implement the new registration requirement, 

and such regulations were expressly declared to be exempt from the Administrative 

Procedure Act (Gov. Code, § 11340 et seq., APA). (§ 30900, subd. (b)(5).) For 

1 The full title of the statutory scheme is the “Roberti-Roos Assault Weapons 

Control Act of 1989 and the .50 Caliber BMG Regulation Act of 2004.” (Pen. Code, 

§ 30500.) Unless otherwise indicated, all further statutory references are to the Penal 

Code.

2 A “bullet-button” weapon is designed to require a tool such as a bullet to remove 

the ammunition feeding device or magazine, usually by using the tool or bullet to depress 

a recessed button or lever shielded by a magazine lock. (See Cal. Code Regs., tit. 11, 

§ 5471.)

3 Additionally at Assembly Bill No. 1135 (2015-2016 Reg. Sess.) (Assembly Bill 

1135.) (See Stats. 2016, ch. 40, § 3; see also Assem. Com. on Public Safety on Sen. Bill 

No. 880 (2015-2016 Reg. Sess.) as amended May 17, 2016 [purpose of law’s revision is 

to remove bullet-button loophole]; Sen. Com. on Public Safety on Sen. Bill No. 880 

(2015-2016 Reg. Sess.) as amended March 28, 2016 [same].)

4 The registration deadline was originally January 1, 2018, but it was subsequently 

changed to July 1, 2018. (Assem. Bill No. 103 (2016-2017 Reg. Sess.) (Assembly Bill

103); Stats. 2017, ch. 17, § 49.) If the registration requirements were met, an individual’s 

lawfully owned bullet-button assault weapons would be grandfathered in and allowed. 

(§ 30680.)
3

convenience, we refer to the above described revisions to AWCA by its 2016 legislative 

bill number -- Senate Bill 880.5

The DOJ proceeded to adopt new registration regulations for registering bulletbutton assault weapons, as required by Senate Bill 880. (See Cal. Code Regs., tit. 11, 

§§ 5469-5478.)6 Plaintiffs7then filed the present action challenging the validity of the 

new regulations on two main grounds: (1) the regulations allegedly exceeded the scope 

of the statutory exemption from the APA and therefore had to comply with the APA, and 

(2) certain of the regulations allegedly sought to impermissibly enlarge or vary the 

statutory definition of assault weapons. The trial court rejected plaintiffs’ challenge in 

toto, finding that the regulations adopted by DOJ were reasonably related to the purpose 

of implementing the registration requirement and did not exceed the scope of DOJ’s 

regulatory authority. Plaintiffs now appeal, raising substantially the same issues as were 

presented in the trial court. We conclude the trial court correctly ruled. The subject 

regulations came within DOJ’s statutory exemption from the APA and are reasonably 

consistent with AWCA’s governing statutes. Accordingly, the judgment of the trial court 

is affirmed.

5 We recognize there was a parallel bill in the State Assembly, i.e., Assembly Bill 

1135, which provided the same statutory revisions as Senate Bill 880. For ease of 

expression, we refer simply to Senate Bill 880 (rather than to both bills) in identifying the 

new law.

6 We refer to the challenged regulations as the registration regulations, or simply the 

regulations. 

7 Plaintiffs are individual gun owners (Danny Villanueva, Niall Stallard, Ruben 

Barrios, Charlie Cox, Mark Stroh, Anthony Mendoza) and an association (California 

Rifle & Pistol Association, Incorporated) that are allegedly impacted by the new 

registration regulations. 
4

FACTS AND PROCEDURAL HISTORY

Bullet-Button Assault Weapons

Under the former version of AWCA applicable before Senate Bill 880 took effect, 

the question of whether certain semi-automatic weapons were classified as assault 

weapons depended on, among other things, whether the weapons had “the capacity to 

accept a detachable magazine.” (See former § 30515, subd. (a)(1), (a)(4); Stats. 2016, ch. 

48, § 3.) A “ ‘detachable magazine’ ” was defined as any ammunition feeding device that 

could be removed readily from the firearm “with neither disassembly of the firearm 

action nor use of a tool being required.” (See former Cal. Code Regs., tit. 11, § 5469, 

subd. (a); cf. Cal. Code Regs., tit. 11, § 5471, subd. (m).) A bullet or cartridge was 

considered a tool. (See former Cal. Code Regs., tit. 11, § 5469, subd. (a).) As a result of 

these definitional standards, where a tool such as a bullet was needed to remove the 

magazine, there was no detachable magazine and the weapon was technically not an 

assault weapon under AWCA, even if in all other respects it could function as an assault 

weapon. This created what was referred to in the legislative committee reports relating to 

Senate Bill 880 as the “bullet button loophole.” (See, e.g., Sen. Com. on Public Safety on 

Sen. Bill No. 880 (2015-2016 Reg. Sess.) as amended March 28, 2016, pp. 5-8; Assem. 

Com. on Public Safety on Sen. Bill No. 880 (2015-2016 Reg. Sess.) as amended May 17, 

2016, pp. 1-6.) The same legislative committee reports reflected a concern that weapons 

which are otherwise functionally the same as illegal assault weapons should not be 

excluded from coverage under AWCA merely because a small tool or bullet is used by 

the gun owner to quickly eject and reload ammunition magazines. It was expressed by 

the bill’s author that unless the bullet-button loophole is closed, “the assault weapon ban 

is severely weakened, and these types of military-style firearms will continue to 

proliferate on our streets and in our neighborhoods.” (Assem. Com. on Public Safety on 

Sen. Bill No. 880 (2015-2016 Reg. Sess.) as amended May 17, 2016, p. 3.) 
5

Senate Bill 880 Closes the Bullet-Button Loophole, Requires Registration 

As noted, in Senate Bill 880 the Legislature closed the bullet-button loophole as to 

particular types of semi-automatic weapons, effective January 1, 2017. It did so by 

modifying the definition of what would constitute an assault weapon under certain 

provisions of section 30515. Under the former wording of subdivision (a)(1) and (a)(4) 

of that section, either a semi-automatic centerfire rifle or a semi-automatic pistol that 

possessed one or more other specified features or attributes would constitute an assault 

weapon if the weapon also had the “capacity to accept a detachable magazine.” (See 

former § 30515, subd. (a)(1), (a)(4); Stats. 2016, ch. 48, § 3.) As we have explained, this 

created a loophole for certain weapons because a magazine was not considered 

“detachable” if a simple tool such as a bullet had to be used to remove it. Under the 

revised statutory definition created by Senate Bill 880, the phrase “the capacity to accept 

a detachable magazine” was deleted from subdivision (a)(1) and (a)(4) of section 30515 

and replaced with the words “does not have a fixed magazine.” (§ 30515, italics added; 

Stats. 2016, ch. 48, § 3.) Moreover, the term “ ‘fixed magazine’ ” was expressly defined 

to mean “an ammunition feeding device contained in, or permanently attached to, a 

firearm in such a manner that the device cannot be removed without disassembly of the 

firearm action.” (§ 30515, subd. (b).) As the latter definition reflects, the mere use of a 

tool to quickly remove the magazine would no longer create an exception. In other 

words, under Senate Bill 880, bullet-button weapons would no longer be automatically 

excluded from the definition of assault weapons under section 30515, subdivision (a)(1) 

and (a)(4), since a magazine that is easily removable with a bullet or other small tool 

plainly “does not have a fixed magazine” as that term is defined under the new law. 

The second major part of Senate Bill 880 was to provide a mechanism to 

grandfather the bullet-button assault weapons that were lawfully owned in California 

prior to the new law. This was largely accomplished through a registration requirement 

set forth in a newly added subdivision (b) to section 30900. (Stats. 2016, ch. 48, § 3.) As 
6

provided in section 30900, subdivision (b), the new registration requirement was as 

follows: 

“(1) Any person who, from January 1, 2001, to December 31, 2016, inclusive,

lawfully possessed an assault weapon that does not have a fixed magazine, as

defined in Section 30515, including those weapons with an ammunition feeding

device that can be readily removed from the firearm with the use of a tool, shall

register the firearm before July 1, 2018, but not before the effective date of the

regulations adopted pursuant to paragraph (5), with the department pursuant to

those procedures that the department may establish by regulation pursuant to

paragraph (5).

“(2) Registrations shall be submitted electronically via the Internet utilizing a

public-facing application made available by the department.

“(3) The registration shall contain a description of the firearm that identifies it

uniquely, including all identification marks, the date the firearm was acquired, the

name and address of the individual from whom, or business from which, the

firearm was acquired, as well as the registrant’s full name, address, telephone

number, date of birth, sex, height, weight, eye color, hair color, and California

driver’s license number or California identification card number.

“(4) The department may charge a fee in an amount of up to fifteen dollars ($15)

per person but not to exceed the reasonable processing costs of the department.

The fee shall be paid by debit or credit card at the time that the electronic

registration is submitted to the department. The fee shall be deposited in the

Dealers’ Record of Sale Special Account to be used for purposes of this section.

“(5) The department shall adopt regulations for the purpose of implementing this

subdivision. These regulations are exempt from the Administrative Procedure Act

(Chapter 3.5 (commencing with Section 11340) of Part 1 of Division 3 of Title 2

of the Government Code).”

As the foregoing statutory provisions make clear, persons who prior to January 1, 

2017, had lawfully possessed an assault weapon that “does not have a fixed magazine,” 

including weapons with a magazine that “can be readily removed from the firearm with 

the use of a tool” – in other words, bullet-button assault weapons – had to register them 

before July 1, 2018. (§ 30900, subd. (b)(1).) To implement this registration requirement, 
7

DOJ was directed in the statute to adopt regulations, and such regulations were declared 

to be exempt from the APA. (§ 30900, subd. (b)(5).)

Finally, under Senate Bill 880, section 30680 was enacted. This section created an 

exemption from the application of section 30605 (the prohibition against the possession 

of an assault weapon) for persons who lawfully possessed bullet-button assault weapons 

prior to January 1, 2017, if they timely satisfied the registration requirements of section 

30900 as set forth in section 30680. (§ 30680.) 

DOJ Adopts Registration Regulations

DOJ adopted new registration regulations for registering bullet-button assault 

weapons, as required by Senate Bill 880, and the regulations were duly published by the 

Office of Administrative Law. The new regulations became effective on July 31, 2017, 

and are published at California Code of Regulations, title 11, sections 5469 through 5478. 

Said regulations cover the following topics or subject matter: a description of the types 

of weapons that must be registered and definitions of the statutory terms governing the 

registration requirements (Cal. Code Regs., tit. 11, §§ 5470-5472); the process for 

registering via DOJ’s website and the information required to be provided (Id. §§ 5473-

5474)8; joint registration requirements (Id. § 5474.1); serial number requirements for 

registering homebuilt weapons (Id. § 5474.2); the required registration fee (Id. § 5475); 

the deadlines for submitting registrations and complying with requests for additional 

information or documentation (Id. § 5476); the prohibition on illegal modifications to 

registered weapons (Id. § 5477); and the process for voluntary deregistration (Id. § 5478). 

Plaintiffs Action Filed in Trial Court Challenging Regulations

On September 7, 2017, plaintiffs filed their complaint in the trial court challenging 

the registration regulations adopted by DOJ. The defendants named in the complaint 

8

It appears that section 5473 of title 11, California Code of Regulations, was 

repealed in 2019. 
8

were Xavier Becerra, in his official capacity as Attorney General for the State of 

California, Stephen Lindley, in his official capacity as Chief of the DOJ Bureau of 

Firearms, and DOJ (collectively DOJ or defendants). The complaint alleged causes of 

action for declaratory and injunctive relief on the grounds that the regulations (1) 

exceeded the scope of the limited APA exemption stated in section 30900, subdivision 

(b)(5), by attempting to do more than implementing a registration program for bulletbutton assault weapons, and (2) sought to impermissibly expand the statutory terms in 

AWCA. Among other things, the complaint asserted that the new regulations added 

numerous definitions of terms (while deleting others) and imposed requirements 

allegedly unrelated to the registration of bullet-button assault weapons. Allegedly, to the 

extent such regulations went beyond the subject of implementing a registration program 

for bullet-button assault weapons, the APA statutory exemption did not apply and DOJ 

was required to follow the formal public comment process of the APA. Additionally, the 

regulations also allegedly exceeded DOJ’s authority by including bullet-button shotguns

in the definition of assault weapons, even though Senate Bill 880 had only referred to 

bullet-button rifles and pistols, not shotguns. 

DOJ filed a demurrer to the complaint, contending among other things that its 

determination to proceed under the statutory exemption from the APA pursuant to section 

30900, subdivision (b)(5), rather than going through the formalities of the APA process 

in adopting the new regulations, was a discretionary administrative decision that can be 

reviewed or challenged only through a writ of mandate, not declaratory relief. The trial 

court sustained the demurrer on that ground, with leave to amend to allow plaintiffs to 

“seek writ relief.” On March 21, 2018, plaintiffs filed an amended pleading – namely, a 

first amended verified petition for writ of mandate and complaint for declaratory and 

injunctive relief (the first amended complaint). While the underlying allegations were 

essentially the same, the first amended complaint added distinct claims seeking review by 

writ of mandate, including on the ground that DOJ abused its discretion by adopting the 
9

new regulations on a “ ‘file and print’ ” basis (i.e., under the APA exemption), rather than 

doing so in accordance with the formal public comment process of the APA. 

Hearing and Order Denying Relief

On May 25, 2018, a hearing was held in the trial court on plaintiffs’ first amended 

complaint to determine whether plaintiffs were entitled to a writ of mandate and/or other 

relief under the first amended complaint. Following oral argument, the matter was taken 

under submission. On May 30, 2018, the trial court issued its order denying the petition 

for writ of mandate and other relief. In its order, the trial court held that DOJ did not 

exceed its proper authority but acted within the parameters of its exemption from the 

APA. According to the trial court, the regulations adopted by DOJ reasonably 

implemented and properly filled in the details of the authorizing statute, thereby carrying 

out the intent of the Legislature that DOJ create a registration program for bullet-button 

assault weapons. Therefore, the trial court denied all relief and judgment was 

subsequently entered in favor of defendants. Notice of entry of judgment was filed on 

July 6, 2018. Plaintiffs timely filed their notice of appeal from the judgment. 

DISCUSSION

I. Standard of Review

As noted, the trial court’s ruling denied all relief under the first amended 

complaint, concluding the regulations did not exceed the scope of the APA exemption 

and were a reasonable and proper implementation of SB 880’s directive that the DOJ 

adopt registration regulations covering the bullet-button assault weapons. Plaintiffs’ 

appeal argues the trial court erred in these conclusions. As explained below, our review 

is primarily de novo.

We consider the proper standard for reviewing the action of a state agency in the 

present context. “Where, as here, the petition seeks a writ of mandate under Code of 

Civil Procedure section 1085, our review is limited to a determination of whether the 

agency’s decision was arbitrary, capricious, entirely lacking in evidentiary support, 
10

unlawful, or procedurally unfair. [Citation.] Independent review is required, however, 

where the issue involves statutory or regulatory construction, such as whether the 

agency’s action was consistent with applicable law.” (California School Bds. Assn. v. 

State Bd. of Education (2010) 186 Cal.App.4th 1298, 1313-1314.) Since the present 

appeal involves statutory or regulatory review and/or the question of whether DOJ’s 

action was consistent with applicable law, we apply independent or de novo review. 

(Western States Petroleum Assn. v. Board of Equalization (2013) 57 Cal.4th 401, 415.) 

“[W]hen an implementing regulation is challenged on the ground that it is ‘in conflict 

with the statute’ [citation] or does not ‘lay within the lawmaking authority delegated by 

the Legislature’ [citation], the issue of statutory construction is a question of law on 

which a court exercises independent judgment.” (Ibid.) To the extent DOJ’s application 

or interpretation of law within its agency expertise is at issue, we exercise our 

independent judgment, but we also consider whether any deference to the determination 

of said agency is appropriate to the circumstances of the agency action. (Yamaha Corp. 

v. America v. State Board of Equalization (1998) 19 Cal.4th 1, 7-8.) 

If the APA is applicable to an agency’s adoption of regulations, any regulations 

that substantially fail to comply with the APA’s procedural requirements may be 

judicially declared invalid. (California School Bds. Assn. v. State Bd. of Education, 

supra, 186 Cal.App.4th at p. 1328.) Such APA questions of law are reviewed by this 

court de novo without deferring to the agency. (Sims v. Department of Corrections &

Rehabilitation (2013) 216 Cal.App.4th 1059, 1071; California Advocates for Nursing 

Home Reform v. Bonta (2003) 106 Cal.App.4th 498, 506.) 

Plaintiffs also challenge the trial court’s demurrer ruling that required plaintiff to 

plead writ of mandate, rather than declaratory relief, for alleged failure to comply with 

the APA. The standard of review on appeal from an order sustaining a demurrer is de 

novo. (California School Bds. Assn. v. State Bd. of Education, supra, 186 Cal.App.4th at 

p. 1313; Blank v. Kirwan (1985) 39 Cal.3d 311, 318.) 
11

II. The Inclusion of Shotguns in the New Regulations – Issue Rendered Moot by 

Subsequent Statutory Amendment

One of plaintiffs’ main contentions in the instant appeal is that the DOJ 

overstepped its authority when it included bullet-button shotguns in the registration 

regulations and required that such shotguns be registered as assault weapons by the July 

1, 2018 deadline. (See Cal. Code Regs., tit. 11, § 5470, subd. (d) [requiring registration 

of semi-automatic shotguns that have a bullet button].) The legal principle behind 

plaintiffs’ argument is that “agencies do not have discretion to promulgate regulations 

that are inconsistent with the governing statute, or that alter or amend the statute or 

enlarge its scope.” (Slocum v. State Bd. of Equalization (2005) 134 Cal.App.4th 969, 

974; Ontario Community Foundations, Inc. v. State Bd. of Equalization (1984) 35 Cal.3d 

811, 816-817; accord, Marshall v. McMahon (1993) 17 Cal.App.4th 1841, 1848.) In 

essence, plaintiffs are contending that DOJ’s inclusion of bullet-button semi-automatic 

shotguns impermissibly sought to expand or enlarge the scope of the governing statute’s 

definition(s) of assault weapons. 

In support of this argument, plaintiffs point out that Senate Bill 880 only revised 

the definition of assault weapons set forth in section 30515, subdivision (a)(1) and (a)(4) 

relating to certain semi-automatic rifles and pistols in order to close the bullet-button 

loophole as to those weapons; however, Senate Bill 880 did not make the same revision 

as to semi-automatic shotguns. (See Stats. 2016, ch. 48, § 1.) Thus, according to 

plaintiffs, the prior definitional standard for whether a semi-automatic shotgun 

constituted an assault weapon remained in effect, which was set forth in subdivision 

(a)(7) of section 30515 as follows: “A semiautomatic shotgun that has the ability to 

accept a detachable magazine.” (Former § 30515, subd. (a)(7); see Cal. Code Regs., tit. 

11, former § 5469, subd. (a), now § 5471, subd. (m) [defining “ ‘[d]etachable 

magazine’ ” as excluding a magazine removable with a bullet or other tool].) In a 

nutshell, plaintiffs maintain that because semi-automatic shotguns with a bullet button 
12

were not redefined by Senate Bill 880 as assault weapons, DOJ went beyond the scope of 

the governing statute and exceeded its authority when it included them among the list of 

weapons that had to be registered as assault weapons under section 30900, subdivision 

(b). 

In response, DOJ asserts that the inclusion of bullet-button semi-automatic 

shotguns in the regulations implementing Senate Bill 880’s registration requirement was 

consistent with the overriding purpose of Senate Bill 880 to protect the public from 

dangerous bullet-button weapons, and in any event such inclusion was arguably 

permissible under the terms of section 30900, subdivision (b)(1), which describes the 

assault weapons to be registered as including “those weapons with an ammunition 

feeding device that can be readily removed from the firearm with the use of a tool.” 

Furthermore, DOJ argues that the inclusion of such shotguns in the registration 

regulations was within the bounds of its broad discretion to fill in the gaps of the 

legislation. 

Having framed the nature of this issue, we conclude that we need not reach it 

because the issue has been rendered moot by subsequent legislative amendment. 

Specifically, section 30515, subdivision (a)(7) was recently amended by the Legislature, 

effective August 6, 2020. Under that amendment, the statutory definition of an “assault 

weapon” was revised regarding shotguns by providing that an assault weapon shall 

include “[a] semiautomatic shotgun that does not have a fixed magazine.” (§ 30515, 

subd. (a)(7); Stats. 2020, ch. 29, § 38 (SB 118).) By replacing the words “has the ability 

to accept a detachable magazine” with “does not have a fixed magazine,” the 2020 

amendment conformed the wording of subdivision (a)(7) to that of subdivisions (a)(1) 

and (a)(4) -- the same wording used by the Legislature in Senate Bill 880 to close the 

bullet-button loophole in those provisions. Thus, the 2020 amendment to subdivision 

(a)(7) of section 30515 clearly added semi-automatic bullet-button shotguns to the 

statutory categories of weapons that would constitute assault weapons. 
13

In light of this substantial change in the law, plaintiffs’ argument that DOJ’s 

registration regulations are improper to the extent the governing statute (i.e., § 30515) 

does not expressly define bullet-button semi-automatic shotguns as assault weapons is 

rendered moot or academic. That is, by virtue of the 2020 amendment revising 

subdivision (a)(7) of section 30515, AWCA now includes bullet-button semi-automatic 

shotguns in the definition of assault weapons. The former statutory deficiency, if any, or 

the former discrepancy between the governing statute and the regulations, if any, has 

been cured by the subsequent amendment. It is well established that an intervening 

change in the law may result in mootness. (See, e.g., Association of Irritated Residents v. 

Department of Conservation (2017) 11 Cal.App.5th 1202, 1222; Callie v. Board of 

Supervisors (1969) 1 Cal.App.3d 13, 18; County of San Diego v. Brown (1993) 19 

Cal.App.4th 1054, 1089-1090; Bravo Vending v. City of Rancho Mirage (1993) 16 

Cal.App.4th 383, 393 [in finding mootness, the version of law in force at present was 

applied on appeal].) This rule of mootness applies to cases pending on appeal. “‘Repeal 

or modification of a statute [or ordinance] under attack, or subsequent legislation, may 

render moot the issues in a pending appeal.’” (Callie v. Board of Supervisors, supra, 1 

Cal.App.3d at pp. 18-19.) That is manifestly the case here. Accordingly, due to 

mootness we decline to reach plaintiffs’ challenge to the regulations premised on the 

“shotgun” issue. (See Consumer Cause, Inc. v. Johnson & Johnson (2005) 132 

Cal.App.4th 1175, 1183 [courts do not consider moot questions or abstract propositions].) 

III. The Entire Appeal Will Not Be Dismissed as Moot

DOJ argues that because the deadline for registration of bullet-button assault 

weapons has expired, the regulations governing the registration process are obsolete, and 

thus plaintiffs’ challenge to those regulations in the present appeal is rendered moot or 

academic. Accordingly, DOJ asks that we dismiss the entire appeal on the ground of 

mootness. We decline to do so, for two reasons. First, if plaintiffs’ claim in this appeal 

that the registration regulations are invalid is determined to be correct, it is unclear 
14

whether that determination may potentially affect whether any of the purportedly 

registered bullet-button assault weapons have in fact been properly or lawfully 

registered.9 Proceeding with this appeal may thus prevent there being a cloud on the 

registrations that have occurred. Accordingly, the case is arguably not rendered moot by 

the mere passage of the registration deadline. Second, the APA serves an important 

public purpose of establishing procedures that provide security against bureaucratic 

tyranny. (See Morning Star Co. v. State Bd. of Equalization (2006) 38 Cal.4th 324, 333

(Morning Star)). Due to the APA’s public importance, we think an alleged failure to 

comply therewith may, in a proper case, be considered on appeal even though a short 

administrative deadline arguably rendered the challenged regulations obsolete. (See, e.g., 

Santa Monica Baykeeper v. City of Malibu (2011) 193 Cal.App.4th 1538, 1548 

[discretionary exceptions to mootness recognized, including where issue is one of public 

interest which may recur].) For these reasons, although we have applied mootness to a 

discrete issue or issues in this appeal due to a subsequent statutory amendment (see, e.g., 

“shotgun” issue above), we decline to dismiss the entirety of plaintiffs’ appeal on the 

basis of mootness allegedly arising from the expiration of the registration deadline. 

IV. The Regulations Were Reasonably Within DOJ’s Authority to Implement 

Bullet-Button Assault Weapon Registration, and Thus Were Exempt from the 

APA

DOJ adopted regulations that implemented a registration process for the 

registration by July 1, 2018, of the newly defined bullet-button assault weapons under 

9 We note it is also not clear that all of the applications to register bullet-button 

assault weapons have been fully processed and determined by DOJ. We grant plaintiffs’ 

request for judicial notice of DOJ’s response to a Public Records Act (Gov. Code, § 6250 

et seq.) request stating that, as of July 11, 2018, over 50,000 applications to register 

bullet-button assault weapons were still being processed. Plaintiffs also sought judicial 

notice of a pleading filed in a different case. That part of the request for judicial notice is 

denied, as the pleading is not relevant to any material issues in this appeal. (People ex 

rel. Lockyer v. Shamrock Foods Co. (2000) 24 Cal.4th 415, 422, fn. 2.)
15

Senate Bill 880. (See Cal. Code Regs., tit. 11, §§ 5469-5478.) Plaintiffs’ attack on the 

validity of these regulations is largely based upon plaintiffs’ contention that the subject 

registration regulations went beyond the scope of the APA exemption that was expressly 

provided in section 30900, subdivision (b)(5). Based on that assumption, plaintiffs 

further contend the adoption of the registration regulations necessarily had to comply 

with the APA’s procedural requirements, and DOJ’s failure to do so invalidates the 

regulations. As a preface to our consideration of plaintiffs’ argument, we briefly outline 

the following background principles of law: (1) the procedural requirements of the APA, 

and (2) the scope of DOJ’s reasonable discretion in adopting regulations. 

A. The APA’s Procedural Requirements

The APA subjects proposed agency regulations to certain procedural requirements 

that must be met for the regulations to become effective. (Morning Star, supra, 38 

Cal.4th at p. 332; see Gov. Code, §§ 11340 et seq.) “‘If a rule constitutes a ‘regulation’ 

within the meaning of the APA ... it may not be adopted, amended, or repealed except in 

conformity with “basic minimum procedural requirements” (citation) that are exacting.” 

(Morning Star, supra, 38 Cal.4th at p. 333.) Any regulation or order of repeal that 

substantially fails to comply with these requirements may be judicially declared invalid. 

(Gov. Code, § 11350; Morning Star, supra, 38 Cal.4th at p. 333; accord, Morales v. 

California Dept. of Corrections & Rehabilitation (2008) 168 Cal.App.4th 729, 735-736 

(Morales).)

Under the APA’s procedural requirements, if a proposed rule constitutes a 

regulation within the meaning of the APA, the following procedural steps must take 

place: “ ‘The agency must give the public notice of its proposed regulatory action 

[citations]; issue a complete text of the proposed regulation with a statement of the 

reasons for it [citations]; give interested parties an opportunity to comment on the 

proposed regulation [citation]; respond in writing to public comments [citations]; and 

forward a file of all materials on which the agency relied in the regulatory process to the 
16

Office of Administrative Law (citation), which reviews the regulation for consistency 

with the law, clarity, and necessity.’ ” (Morning Star, supra, 38 Cal.4th at p. 333.)

Unless expressly exempted, all administrative regulations must comply with the 

APA. (State Water Resources Control Bd. v. Office of Admin. Law (1993) 12 

Cal.App.4th 697, 704; see Gov. Code, § 11346; see Pacific Legal Foundation v. 

California Coastal Com. (1982) 33 Cal.3d 158, 169, fn. 4 [noting “because the 

Legislature specifically exempted the guidelines from the provisions of [the APA],” no 

review under APA declaratory relief statute was available].) When the Legislature seeks 

to exempt regulations from the APA, it does so by clear, unequivocal language. (United 

Systems of Arkansas, Inc. v. Stamison (1998) 63 Cal.App.4th 1001, 1010.) Doubts as to 

the applicability of the APA’s requirements should be resolved in favor of the APA. 

(Morales, supra, 168 Cal.App.4th at p. 736.) 

Here, as noted, an explicit exemption from the APA was provided by the 

Legislature in section 30900, subdivision (b)(5). In section 30900, subdivision (b)(1) 

through (b)(4), which is the portion of the subdivision preceding the exemption language, 

the requirement is stated for bullet-button assault weapons to be registered by a certain 

date, including an electronic or internet “public-facing” registration format, and among 

other things it is specified that such registration process shall include the provision of 

information to uniquely describe and identify the firearm, the registrant’s identity, and 

shall include the payment of a fee. After these core registration contents are stated, the 

APA exemption states as follows: “The department shall adopt regulations for the 

purpose of implementing this subdivision. These regulations are exempt from the

Administrate Procedure Act.” (Italics added.) Thus, it is clear the Legislature, in 

enacting Senate Bill 880, intended that regulations adopted by DOJ to reasonably 

implement the registration requirement would be exempt from the APA.
17

B. The Agency’s Broad Discretion

For purposes of our review of plaintiffs’ challenge to the validity of the 

registration regulations adopted by DOJ, it is necessary to consider the nature of DOJ’s 

agency discretion, our standard of review thereof, and the degree of deference, if any, that 

should be shown. 

The California Supreme Court recently summarized the guiding principles for 

review of cases such as this, as follows: “‘Deference to administrative interpretations 

always is “situational” and depends on “a complex of factors” [citation], but where the 

agency had special expertise and its decision is carefully considered by senior agency 

officials, that decision is entitled to correspondingly greater weight.’ [Citation.] Where 

an agency’s action is ‘quasi-legislative’ or ‘the substantive product of a delegated 

legislative power conferred on the agency,’ the scope of our review is ‘limited to 

determining whether the regulation (1) is “within the scope of the authority conferred”

[citation] and (2) is “reasonably necessary to effectuate the purpose of the statute”

[citation.]’ [Citation.] By contrast, where an agency’s action is interpretive or merely 

‘represents the agency’s view of the statute’s legal meaning and effect,’ the agency’s 

‘interpretation of the meaning and legal effect of a statute is entitled to consideration and 

respect,’ ‘but commands a commensurably lesser degree of judicial deference.’ 

[Citation.] [¶ ] Although the classification of an agency’s action as quasi-legislative or 

interpretive often guides our analysis, we have observed that ‘some rules defy easy 

categorization.’ [Citation.] ... [I]n certain circumstances, a regulation may have both 

quasi-legislative and interpretive characteristics – “as when an administrative agency 

exercises a legislatively delegated power to interpret key statutory terms.” ’ ” 

(Christensen v. Lightbourne (2019) 7 Cal.5th 761, 771-772.) 

Here, DOJ was directed to implement a registration program within the purposes 

of section 30900, subdivision (b)(1) to (b)(4). Such a directive clearly gave to DOJ a 

quasi-legislative authority to accomplish that purpose. Thus, the scope of our review is 
18

limited to determining whether the challenged regulations are (1) within the scope of the 

authority conferred and (2) is reasonably necessary to effectuate the purpose of the 

statute. (Christensen v. Lightbourne, supra, 7 Cal.5th at p. 771.) Where the Legislature 

has, as here, delegated to an agency the responsibility to implement a statutory scheme 

through regulations, a reviewing court will not interfere unless “the agency has clearly 

overstepped its statutory authority or violated a constitutional mandate.” (Ford Dealers 

Assn. v. Department of Motor Vehicles (1982) 32 Cal.3d 347, 355-356, italics added.) 

“ ‘ “ ‘The scope of our review of an administrative agency’s regulations is limited: we 

consider whether the challenged provisions are consistent and not in conflict with the 

enabling statute and reasonably necessary to effectuate its purpose.’ ” ’ ” (Masonite 

Corp. v. County of Mendocino Air Quality Management Dist. (1996) 42 Cal.App.4th 436, 

447, italics added.) 

In undertaking this review, we also keep in mind that the regulations under 

consideration need not simply mirror the statutory language, but may fill in details to 

further the purpose of the governing legislation: “ ‘ “ ‘In enacting such rules and 

regulations, the Board is empowered to fill up the details of the enabling legislation. 

[Citation.] The court’s role is to decide whether in enacting the specific rule the [agency] 

reasonably interpreted the legislative mandate.’ ” ’ ” (Masonite Corp. v. County of 

Mendocino Air Quality Management Dist., supra, 42 Cal.App.4th at p. 447.) ‘“An 

administrative agency is not limited to the exact provisions of a statute in adopting 

regulations to enforce its mandate. “[The] absence of any specific [statutory] provisions 

regarding the regulation of [an issue] does not mean that such a regulation exceeds 

statutory authority ....’ [Citations.] The [administrative agency] is authorized to “ ‘fill 

up the details’ ” of the statutory scheme.’ ” (PaintCare v. Mortensen (2015) 233 

Cal.App.4th 1292, 1307; accord, Batt v. City and County of San Francisco (2010) 184 

Cal.App.4th 163, 171.) Similarly, the agency’s authority also includes the power to 

elaborate the meaning of statutory terms. (GMRI, Inc. v. California Dept. of Tax & Fee 
19

Administration (2018) 21 Cal.App.5th 111, 125.) It is also a well-settled principle of 

administrative law that in the absence of an express statutory directive to the contrary, an 

agency may exercise its discretion in selecting the methodology by which it will 

implement the authority granted to it. (Community Water Coalition v. Santa Cruz County 

Local Agency Formation Com. (2011) 200 Cal.App.4th 1317, 1328.)

In determining whether an agency has incorrectly interpreted the statute it purports 

to implement, a court generally gives weight to the agency’s construction. (Western 

States Petroleum Assn. v. Board of Equalization (2013) 57 Cal.4th 401, 415.) 

“ ‘Nevertheless, the proper interpretation of a statute is ultimately the court’s 

responsibility.’ ” (Id. at pp. 415-416.) “‘When a regulation is challenged on the ground 

that it is not “reasonably necessary to effectuate the purpose of the statute,” our inquiry is 

confined to whether the rule is arbitrary, capricious, or without rational basis [citation] 

and whether substantial evidence supports the agency’s determination that the rule is 

reasonably necessary [citation].’ [Citation.] The question of ‘reasonable necessity’ 

generally implicates the agency’s expertise; therefore it receives a much more deferential 

standard of review.” (Delta Stewardship Council Cases (2020) 48 Cal.App.5th 1014, 

1048.) 

The party challenging a regulation has the burden to show its invalidity. (Delta 

Stewardship Council Cases, supra, 48 Cal.App.5th at p. 1049.) 

C. The Regulations Were Reasonably Necessary to Accomplish Statutory 

Mandate

The trial court concluded the regulations were reasonably necessary to the 

accomplishment of the statutory purpose of creating an effective registration process for 

bullet-button assault weapons, and the regulations were also reasonably within DOJ’s 

authority to fill in the details of the legislation. Accordingly, the trial court concluded 

that plaintiffs had failed to show DOJ exceeded the scope of the APA exemption. As the 

trial court expressed in its order: “DOJ is authorized to ‘adopt regulations for the purpose 
20

of implementing’ the authorizing statute. [Citation.] The regulations at issue here each 

appear to do just that, such that the APA exemption would apply. The challenged 

regulations ensure that eligible weapons are registered, by eligible applicants, through an 

understandable registration process.” 

Based on our independent review, we conclude the trial court was correct. As we 

have noted hereinabove, section 30900, subdivision (b)(5), delegated quasi-legislative 

power to DOJ to create a registration program for bullet-button assault weapons. In 

doing so, DOJ was not limited by the specific language of section 30900, subdivision (b), 

but could appropriately fill in the details of what was reasonably needed to accomplish an 

effective registration program. As more fully discussed below, that appears to be 

precisely what DOJ did in adopting the regulations at issue in this appeal. Further, 

plaintiffs have failed to meet their burden of demonstrating the invalidity of any of the 

regulations.

Below, we consider plaintiffs’ main arguments raised as to specific aspects of the 

registration regulations.

1. The Breadth of the Regulations

Plaintiffs generally object that the registration regulations “concern themselves not 

[merely] with how to register ‘bullet-button assault weapons,’ but instead with what may 

be registered, who may register, or the conditions for registration.” But plaintiffs, whose 

burden it is to affirmatively demonstrate the regulations’ invalidity (Delta Stewardship 

Council Cases, supra, 48 Cal.App.5th at p. 1049), offer no adequate explanation why 

regulations implementing an effective registration process should not address these key 

topics. Moreover, as DOJ has cogently explained, implementing an effective bulletbutton assault weapon registration program reasonably required addressing several 

interrelated matters: “To administer the registration process, DOJ found it necessary to 

promulgate regulations that make it possible to: determine the types of firearms that can 

be registered (registration definitions); register weapons that the Legislature has required 
21

to be registered (registration of bullet-button [assault weapons]); obtain information 

necessary to uniquely identify each registered weapon (serial number and digital photo 

requirements) or confirm an applicant’s eligibility to register a firearm (registration 

information requirements); prevent abuse of the joint registration option (‘family 

member’ definition and proof-of-address requirements); establish parameters for the 

electronic registration process required by law (terms of use); and prohibit subsequent 

modification of registered weapons into weapons that first became prohibited almost 

twenty years ago, and have been unlawful to acquire since then (modification 

prohibition).... [T]hese regulations ensure that only eligible weapons are registered, only 

by eligible applicants, through a transparent, reliable process.” 

We find DOJ’s explanation to be persuasive. The topics covered by the 

regulations may be broad, but they are interrelated and reasonably impact whether the 

registration system implemented by DOJ will be understandable, reliable and effective. 

Further, DOJ is within its discretion to fill in such details to accomplish the legislative 

purpose. (See PaintCare v. Mortensen, supra, 233 Cal.App.4th at p. 1307.) We 

conclude the registration regulations at issue herein were within the scope of the authority 

conferred and reasonably necessary to effectuate the statutory purpose. (See Christensen 

v. Lightbourne, supra, 7 Cal.5th at p. 771.) Additionally, we note “the question of 

‘reasonable necessity’ generally implicates the agency’s expertise; therefore it receives a 

much more deferential standard of review.” (Delta Stewardship Council Cases, supra, 

48 Cal.App.5th at p. 1048.) For all these reasons, we reject plaintiffs’ argument that the 

breadth of the topics covered in the regulations means they were outside the bounds of 

the APA exception set forth in section 30900, subdivision (b)(5).

2. Inclusion of Bullet-Button Shotguns

We have already addressed in this opinion, plaintiffs’ contention that the 

regulations impermissibly included the registration of bullet-button shotguns because, as 

was noted by plaintiffs, Senate Bill 880 only amended the definition of assault weapons 
22

to include bullet-button rifles and pistols. As we concluded hereinabove, the question has 

been rendered moot by subsequent statutory amendment. That is, under a 2020 

amendment revising subdivision (a)(7) of section 30515, AWCA now includes bulletbutton semi-automatic shotguns in the definition of assault weapons. (§ 30515, subd. 

(a)(7) [an assault weapon includes “a semiautomatic shotgun that does not have a fixed 

magazine”]; Stats. 2020, ch. 29, § 38.) As previously explained, due to this issue 

becoming moot, we decline to reach it.

3. Consolidation of Definitions Related to Bullet-Button Registration 

Process

 Plaintiffs challenge the validity of the definitional provisions contained in the 

registration regulations (see Cal. Code Regs., tit. 11, § 5471) as going beyond the scope 

of the APA exemption. Plaintiffs’ argue that DOJ, in adopting the subject regulations, 

repealed five valid definitions in former section 5469 of the California Code of 

Regulation that had been applicable to the identification of assault weapons – which 

repeal would have required APA compliance. However, as correctly pointed out by DOJ, 

plaintiffs’ argument fails because the subject definitional provisions were not repealed, 

but simply consolidated to a new location. (See former Cal. Code Regs., tit. 11, § 5469 

[former site of five definitions for purposes of § 30515]; cf. Cal. Code Regs., tit. 11, 

§§ 5469, 5471 [new location of definitional provisions].) Two of the subject definitions 

(i.e., “forward pistol grip” and “thumbhole stock”) were moved to section 5471 of the 

regulations without change. (Cal. Code Regs., tit. 11, § 5471, subds. (t), (qq).) The 

remaining three (i.e., “ ‘detachable magazine,’ ” “ ‘flash suppressor,’ ” and “ ‘pistol grip 

that protrudes conspicuously beneath the action of the weapon’ ”) were moved to 

California Code of Regulations section 5471 of the regulations without substantial 

change, with specific qualifying examples added. (Cal. Code Regs., tit. 11, § 5471, 

subds. (m), (r), (z).) Certainly, it would be within DOJ’s reasonable discretion in 

establishing an effective registration program to have definitions consolidated in one 
23

place – i.e., a single section of the regulations containing the registration definitions -- to 

reduce confusion during the registration process. In any event, no actual repeal or 

deletion has been shown. Based on the foregoing, we reject plaintiffs’ contention that 

certain definitions were improperly repealed or deleted under the registration regulations. 

Plaintiffs’ second argument challenging the definitional provisions of the 

registration regulations (see Cal. Code Regs., tit. 11, § 5471) is that some of the terms 

defined therein are not specifically related to the registration of bullet-button assault 

weapons. Based on that premise, plaintiffs argue the definitional provisions exceeded the 

APA exemption, and thus APA procedures had to be followed. We disagree. As DOJ 

persuasively maintains, the subject definitions are relevant to the registration process by 

helping clarify and summarize much of the technical statutory terminology referred to in 

section 30515 for purposes of implementing the registration requirement of section 

30900, subdivision (b). Among other things, setting forth such definitions would appear 

to be reasonably necessary for the public to readily understand what types of weapons 

would constitute a bullet-button assault weapon, and what types of weapons would not, 

under the various technical terms.10 

As the trial court correctly observed, “[t]he APA exemption granted by the 

Legislature would appear to include the power to define terms to enable the public to 

understand and comply with the registration process.” Additionally, DOJ’s assessment of 

10

 We note the majority of the definitions provided in section 5471 of the California 

Code of Regulations are clearly relevant to the registration process by either (1) 

summarizing and clarifying various basic or technical terminology used to define and 

differentiate types of assault weapons, and/or by (2) specifically defining essential terms 

for whether a particular weapon has the features or attributes that would make it a bulletbutton assault weapon for purposes of the registration requirement. (See, e.g., Cal. Code 

Regs., tit. 11, §§ 5471, subds. (a), (b), (c), (e), (f), (j), (m), (n), (p), (q), (r), (t), (v), (y), 

(z), (ee), (gg), (hh), (ll), (nn), (pp), (qq), (rr); compare, 30515, subd. (a)(1), (a)(4) & 

(a)(7).) Other definitional provisions appear to be indirectly relevant to the process of 

registration, such as by identifying unique features that may need to be reported when 

registering (e.g., Cal. Code Regs., tit. 11, § 5471, subds. (d) & (x) [re: barrel length]).
24

what definitional provisions would be reasonably necessary to facilitate the statutory 

purpose of implementing an effective registration program under section 30900,

subdivision (b), as well as to reasonably fill-in the details thereof, were matters within its 

considerable agency expertise to which deference is appropriate. (See Yamaha Corp. of 

America v. State Bd. of Equalization, supra, 19 Cal.4th at pp. 11-12.) For all the 

foregoing reasons, we conclude that the definitional provisions adopted by DOJ in the 

registration regulations (i.e., Cal. Code of Regs., tit. 11, § 5471) were within the scope of 

the statutory authority conferred upon DOJ by section 30900, subdivision (b)(5) and were 

reasonably necessary to effectuate the purpose of the statute. Accordingly, the definitions 

did not exceed the scope of the APA exemption.

We note further that, according to DOJ, plaintiffs’ argument the requirements of 

the APA had to be followed as to the definitional provisions has arguably been rendered 

moot because of subsequent regulatory action. That is, in January 2019, a separate 

regulation promulgated by DOJ under the APA’s procedural requirements became 

effective, which regulation incorporates by reference each of the definitions set out in 

section 5471 of the registration regulations. This separate regulation, codified as section 

5460 of title 11, California Code of Regulations, provides as follows: “The definitions of 

terms in section 5471 of this chapter shall apply to the identification of assault weapons 

pursuant to Penal Code section 30515.” (Cal. Code Regs., tit. 11, § 5460.) By and 

through the adoption of this separate regulation which incorporates by reference the 

definitions at issue, the subject definitional provisions have apparently been vetted 

through the APA procedures, which arguably renders plaintiffs’ challenge thereof moot. 

DOJ argues we should so hold. However, we do not rely on mootness in rejecting 

plaintiffs’ APA-based challenge of the definitional provisions, primarily because APA 

compliance as to the separate regulation (i.e., Cal. Code Regs., tit. 11, § 5460) has not 

been adequately developed by citation to the record or judicially noticeable facts. 
25

4. The Serial Number Requirement

Plaintiffs challenge the requirement of serial numbers in connection with the 

registration of bullet-button assault weapons manufactured by an unlicensed subject (also 

referred to as FMBUS or home-built firearms), which serial number would be assigned 

by DOJ prior to the home-built weapon’s registration. (Cal. Code Regs., tit. 11, §§ 5472, 

subds. (f) & (g); 5474.2.) Plaintiffs contend this requirement goes beyond the scope of 

the governing statute and exceeds DOJ’s regulatory discretion. We disagree. Section 

30900, subdivision (b)(3) expressly requires that the registration of an assault weapon 

include descriptive information necessary to identify it uniquely. In carrying out that 

mandate, it was within DOJ’s reasonable authority to require such home-built assault 

weapons have an assigned serial number. As explained by DOJ: “DOJ-issued serial 

numbers for registered homebuilt weapons will allow law enforcement to positively 

identify such weapons if they are encountered in the field, are used in a crime, or need to 

be confiscated from persons prohibited from possessing firearms. Owner-selected serial 

numbers (e.g., the initials of the person who built the weapon and the date it was built) 

would not ensure a unique identifier, because unlike serial numbers applied by federally 

licensed manufacturers, another owner may assign another weapon the same identifier.” 

These concerns specifically relating to the need for more adequate and stable 

identification of home-built weapons reflects that the challenged regulations were 

reasonably necessary.

We conclude plaintiffs’ challenge of the serial-number requirement for home-built 

assault weapons fails. Moreover, because the subject regulations were proper when 

adopted, which is a sufficient basis to reject plaintiffs’ challenge, we need not consider 

whether subsequent legislation (i.e., § 29180, subd. (b) [serial number requirement]) 

taking effect after the registration deadline may have potentially supplanted these 

particular regulations.
26

5. The Non-Liability Clause

Plaintiffs challenge former regulation section 5473, which had included a 

provision limiting DOJ’s liability with respect to posting of information electronically. 

The subject regulation has subsequently been repealed (former Cal. Code Regs., tit. 11, 

§ 5473). Therefore, any challenge thereof has been rendered moot and we do not address 

plaintiffs’ contention.

6. Required Registration Information

Plaintiffs argue that some of the personal information required for registration by 

California Code of Regulations, title 11, section 5474, subdivision (a), was improper 

because it went beyond the core information stated by section 30900, subdivision (b)(3). 

Section 30900, subdivision (b)(3), provides that registrants must provide among other 

information their “full name, address, telephone number, date of birth, sex, height, 

weight, eye color, hair color, and California driver’s license number or California 

identification card number.” The challenged regulation requires further information such 

as military identification number (if applicable), place of birth, country of citizenship, 

and alien registration number or I-94, if applicable. (Cal. Code Regs, tit. 11, § 5474.) 

We reject plaintiffs’ argument because there is no merit to the assumption that the 

regulations must only repeat the authorizing statute. (PaintCare v. Mortensen, supra, 233 

Cal.App.4th at p. 1307; accord, Batt v. City and County of San Francisco, supra, 184 

Cal.App.4th at p. 171.) Rather, as we have noted, an administrative agency is authorized 

to fill up the details of the statutory scheme, in order to accomplish the statutory purpose. 

(PaintCare v. Mortensen, supra, p. 1307.) Integral to an effective registration process, 

DOJ must be able to confirm that applicants are not prohibited by state or federal law 

from possessing a firearm, prior to registration. (§ 30950.) The additional information 

requested in the regulation was clearly relevant to that purpose. (See 18 U.S.C. § 922, 

subd. (g).) 
27

Plaintiffs also challenge the requirement for “clear digital photos” (Cal. Code 

Regs., tit. 11, § 5474, subd. (c)) based on the statute’s reference to providing a 

“description” rather than a literal “depiction” of the firearm (see § 30900, subd. (b)(3)). 

But, as we have emphasized, “ ‘[a]n administrative agency is not limited to the exact 

provisions of a statute in adopting regulations to enforce its mandate.” (Paintcare v. 

Mortensen, supra, 233 Cal.App.4th at p. 1307.) Clear digital photographs would 

reasonably assist in uniquely identifying the weapon, as required by statute, and would 

also allow DOJ to confirm that the weapon was accurately described in the application 

and is eligible for registration (e.g., whether it has a bullet button). 

We conclude the informational requirements set forth in this regulation were 

consistent with the statutory purpose and reasonably necessary to implement an effective 

registration process.

7. Joint Registration Requirements

One of the registration regulations adopted by DOJ addressed the qualifications 

for a joint registration by family members in the same household. (Cal. Code Regs., tit. 

11, § 5474.1, subd. (b).) The regulation stated that joint registrants must have one of the 

following family relationships: “(1) Spouses [¶ ] (2) Parent to Child [¶ ] (3) Child to 

Parent [¶ ] (4) Grandparent to Grandchild [¶ ] (5) Grandchild to Grandparent [¶ ] (6) 

Domestic Partners [¶ ] (7) Siblings.” (Id.) In challenging this regulation, plaintiffs argue 

that another statute, i.e., section 30955, provides for joint registration of assault weapons 

“owned by family members residing in the same household.” According to plaintiffs, 

since section 30955 does not limit the nature of the family relationships that may qualify, 

it was improper for DOJ to do so here, or at least it could not do so within the scope of 

the APA exemption -- i.e., APA procedures had to be followed. DOJ responds that its 

regulation specifying the family relationships that qualify for joint registration of bulletbutton assault weapons was within its quasi-legislative authority to implement the 
28

registration process concerning such weapons, as a means of preventing the joint 

registration option from being misused. 

We agree with DOJ that the adoption of regulations to implement an effective 

registration process for bullet-button assault weapons may reasonably include the 

adoption of measures to prevent abuses of that process. Furthermore, section 30955, 

subdivision (a), states in full: “The department’s registration procedures shall provide 

the option of joint registration for any assault weapon... owned by family members 

residing in the same household.” (Italics added.) Since DOJ was mandated under the 

terms of section 30900, subdivision (b)(5), to implement registration procedures for 

bullet-button assault weapons, the issue of joint registration was appropriately 

considered. It was also within DOJ’s agency expertise to have recognized that aspects of 

joint registration may be subject to misuse. On balance, we conclude that the regulation 

supplying a reasonable interpretation of “family members” for purposes of determining 

how to administer the joint registration of bullet-button assault weapons was properly 

within the purview of DOJ’s quasi-legislative authority conferred in this case, and came 

within the APA exemption. (See, e.g., Association of California Ins. Companies v. Jones

(2017) 2 Cal.5th 376, 399 [the Legislature may grant an administrative agency broad 

authority to apply its expertise in determining whether and how to address a matter 

requiring regulation].) 

8. Prohibition on Modification of the Registered Weapons

California Code of Regulations, title 11, section 5477 states that “[t]he release 

mechanism for an ammunition feeding device on an assault weapon registered pursuant 

to Penal Code section 30900, subdivision (b)(1) shall not be changed after the assault 

weapon is registered.” In short, this regulation prevents a bullet-button assault weapon 

from being converted into a weapon that was prohibited and could not have been lawfully 

registered under Senate Bill 880, such as by the removal of the bullet-button mechanism 

to create a quick-release assault weapon. We reject plaintiffs’ challenge of this 
29

regulation. As persuasively argued by DOJ: “It cannot be that the Legislature intended 

to allow the bullet-button assault weapon registration process to be used as a means of 

manufacturing previously prohibited assault weapons. DOJ’s authority to implement the 

registration process necessarily includes authority for regulations securing the registration 

process against this type of abuse, which would undermine assault weapons restrictions 

that have been on the books for decades. The regulation is thus related to and reasonably 

necessary for the registration process.” We agree with DOJ’s argument and conclude this 

regulation was within DOJ’s statutory authority and reasonably necessary to effectuate 

the purpose of the law.

V. Any Error in Demurrer Ruling Was Not Prejudicial 

Plaintiffs argue the trial court erred by sustaining DOJ’s demurrer on the ground 

that plaintiffs could only proceed by traditional mandamus, rather than declaratory relief. 

On this question, we note that it does appear our courts have allowed questions of APA 

compliance, including issues of whether exemptions or exceptions to the APA were 

applicable, to be addressed by claims for declaratory relief. (See, e.g., California School 

Bds. Assn. v. State Bd. of Education, supra, 186 Cal.App.4th at p. 1335 [APA questions 

raised in causes of action that included declaratory relief]; California Advocates for 

Nursing Home Reform v. Bonta (2003) 106 Cal.App.4th 498, 504 [APA questions 

presented by a complaint seeking declaratory and injunctive relief along with writ of 

mandate under Code Civ. Proc., § 1085]; see also, Morales v. California Dept. of 

Corrections & Rehabilitation, supra, 168 Cal.App.4th at p. 735 [holding APA applied to 

certain prison regulations, rejecting applicability of exception, and declaring regulations 

invalid for failure to comply with APA procedures].) Further, this would appear to be 

consistent with the general principle that where the nature of the action being challenged 

is quasi-legislative in character, such as an agency’s adoption of regulations, it is 

reviewable by traditional writ of mandate or by declaratory relief under section 1060 of 

the Code of Civil Procedure. (See, e.g., Pacific Legal Foundation v. California Coastal 
30

Com., supra, 33 Cal.3d at pp. 168-169; Simi Valley Adventist Hosp. v. Bonita (2000) 81 

Cal.App.4th 346, 354; see also, Gov. Code, § 11350, subd. (a) [expressly authorizing 

declaratory relief under APA].)11

But even assuming the trial court erred in its demurrer ruling, we would conclude 

there was no prejudice. Our explanation of lack of prejudice requires some further 

elaboration of the procedural background, which we set forth below. 

As previously outlined hereinabove, plaintiffs’ original complaint included causes 

of action for declaratory relief seeking a judicial determination that the registration 

regulations, or provisions thereof, were invalid because, among other things, DOJ failed 

to comply with the APA’s procedural requirements. The complaint acknowledged the 

statutory exemption from the APA under section 30900, subdivision (b)(5), but alleged 

the exemption did not apply because the subject matter of the regulations exceeded the 

scope of the APA exemption and even impermissibly sought to alter or expand the terms 

of the governing statute. DOJ demurred to the complaint on the ground that the only 

proper vehicle for plaintiffs’ challenge was a petition for writ of mandate, rather than an 

action for declaratory relief. (See Tejon Real Estate, LLC v. City of Los Angeles (2014) 

223 Cal.App.4th 149, 155 [demurrer may be sustained where the complaint attempts to 

obtain review of an agency’s administrative decision via declaratory relief rather than 

mandamus].) In support of this ground for demurrer, DOJ argued plaintiffs were 

11 Government Code section 11350 of the APA specifically provides that “Any 

interested person may obtain a judicial declaration as to the validity of any regulation ... 

by bringing an action for declaratory relief in the superior court in accordance with the 

Code of Civil Procedure.” (Gov. Code, § 11350, subd. (a).) However, section 11350 is 

not available where the regulations were within a statutory exemption to the APA. 

(Pacific Legal Foundation v. California Coastal Com., supra, 33 Cal.3d 158 at p. 169, fn. 

4.) But here, the crux of the matter was the legal question of whether the regulations 

were within the scope of the APA exemption. In any event, we note plaintiffs did not 

rely exclusively on Government Code section 11350, but also sought declaratory relief 

under Code of Civil Procedure section 1060. 
31

essentially challenging DOJ’s discretionary administrative decision that adopting the 

registration regulations did not require APA compliance but could be done through the 

expedited “file and print” process because the regulations came within the scope of the 

statutory exemption. 

Plaintiffs opposed the demurrer, arguing they were not seeking review of any 

administrative decision by DOJ, but were instead challenging the validity of the 

regulations themselves based on DOJ’s failure to comply with the APA and also based on 

allegations the regulations were inconsistent with or sought to alter or expand the 

AWCA. 

The trial court agreed with DOJ’s characterization of the challenged action as an 

administrative decision and, accordingly, sustained DOJ’s demurrer to the complaint with 

leave to amend. Plaintiffs filed a first amended complaint. In substance, the first 

amended complaint appears to have retained the declaratory relief causes of action intact, 

while adding separate claims for relief by writ of mandate.12 After the first amended 

complaint was filed, plaintiffs notified the parties of a hearing date to determine the 

merits of their claims for writ of mandate and declaratory relief. Following that hearing, 

the trial court issued its order denying all relief under the first amended complaint. 

Although the trial court’s order analyzed plaintiffs’ claims within the framework of writ 

of mandate, the trial court nonetheless addressed plaintiffs’ various legal challenges to 

the regulations and reached the following disposition: “[T]he petition [for] writ of 

mandate, and declaratory and injunctive relief, is denied.” 

Based on the above procedural history and our assessment of the trial court’s order 

denying all relief under the first amended complaint, we conclude that regardless of how 

the causes of action were formally denominated in the pleading, the substance of the 

12 Since plaintiffs did not amend the declaratory relief claims, it does not appear that 

plaintiffs waived the right to challenge the demurrer ruling as to those claims.
32

dispositive legal questions in this case were declared and decided, including the questions 

of whether DOJ failed to comply with the APA and whether the regulations came within 

the scope of the statutory exemption. We have likewise addressed those same legal 

questions in the present appeal. Here, as the trial court did, we have concluded that 

plaintiffs have failed to demonstrate the invalidity of the regulations, either under the 

APA or an alleged conflict with the AWCA. In summary, even assuming the trial court’s 

ruling on demurrer was incorrect, it has made no material difference to the outcome or 

resolution of the dispositive legal questions. For these reasons, we conclude that even if 

the trial court’s demurrer ruling was erroneous, any such error was not prejudicial and is 

not ground for reversal.13

DISPOSITION

The judgment of the trial court is affirmed. Defendants are entitled to an award of 

costs on appeal.

SMITH, J.

WE CONCUR:

HILL, P.J.

DE SANTOS, J.

13 Also, inasmuch as we have upheld the validity of the regulations, there is no actual 

or present controversy. (See Canova v. Trustees of Imperial Irrigation Dist. Employee 

Pension Plan (2007) 150 Cal.App.4th 1487, 1497 [declaratory relief is appropriate only 

for actual present controversy, not to redress past wrongs].)