Case Title: American Civil Liberties Union Foundation of Southern California v. Superior Court of Los Angeles County

Citation: 

Docket Number: S227106

State: california

Court: California Supreme Court

Date: 2017-08-31T00:00:00Z

Document:
Filed 8/31/17 
 
 
 
IN THE SUPREME COURT OF CALIFORNIA 
 
 
 
AMERICAN CIVIL LIBERTIES UNION  ) 
FOUNDATION OF SOUTHERN  
) 
CALIFORNIA et al., 
) 
 
 
) 
 
Petitioners, 
) 
 
 
) 
S227106 
 
v. 
) 
 
 
) 
Ct.App. 2/3 B259392 
THE SUPERIOR COURT OF  
) 
LOS ANGELES COUNTY, 
) 
 
) 
Los Angeles County 
 
Respondent; 
) 
Super. Ct. No. BS143004 
 
 
) 
COUNTY OF LOS ANGELES et al., 
) 
 
 
) 
 
Real Parties in Interest. 
) 
 
____________________________________) 
 
Real parties in interest, the Los Angeles Police Department (LAPD) of the 
City of Los Angeles and the Los Angeles Sheriff’s Department (LASD) of the 
County of Los Angeles (collectively, real parties) employ automated license plate 
reader (ALPR) technology in order to locate vehicles linked to crimes under 
investigation.  The American Civil Liberties Union Foundation of Southern 
California (ACLU) and Electronic Frontier Foundation (collectively, petitioners) 
filed a request under the California Public Records Act (CPRA) for all ALPR data 
2 
collected during a one-week period.  (Gov. Code, § 6250 et seq.)1  Petitioners 
sought disclosure of this ALPR data “so that the legal and policy implications of 
the government’s use of ALPRs to collect vast amounts of information on almost 
exclusively law-abiding [citizens of Los Angeles] may be fully and fairly 
debated.”  
We initially granted review to determine whether the requested ALPR data 
are exempt from disclosure as falling within the CPRA provision protecting police 
and state “[r]ecords of . . . investigations” under section 6254, subdivision (f) 
(section 6254(f)).  As relevant here, section 6254(f) protects from disclosure:  
“Records of investigations conducted by . . . any state or local police agency.”2  
After granting review, we requested additional briefing on a second issue:  
Whether the catchall exemption in section 6255, subdivision (a) (section 6255(a)) 
authorizes real parties to withhold the requested ALPR data.  Under section 
6255(a), a public agency may “justify withholding any record by demonstrating 
that on the facts of the particular case the public interest served by not disclosing 
the record clearly outweighs the public interest served by disclosure of the 
record.”   
Petitioners conceded in the trial court that section 6254(f) protects from 
disclosure the ALPR license plate scan data that matches vehicles linked to law 
enforcement investigations under section 6254(f).  They do not argue that real 
parties’ use of the ALPR technology is unlawful.  They contend only that ALPR 
scan data are not exempt from disclosure under the CPRA. 
                                              
1 
All further statutory references are to the Government Code, unless 
otherwise specified. 
2  
There is no dispute that ALPR data are public records (see § 6252, subd. 
(e)) and no dispute that real parties are police agencies subject to the CPRA. 
3 
The trial court determined that the data requested came within section 
6254(f)’s “[r]ecords of . . . investigations” exemption.  The court also concluded 
that section 6255(a)’s catchall provision authorized real parties to withhold the 
data.  The Court of Appeal affirmed the judgment based on section 6254(f), 
without reaching the section 6255(a) question.  In light of our constitutional 
obligation to broadly construe the CPRA in a manner that furthers the people’s 
right of access to the conduct of governmental operations, and to narrowly 
construe any exemptions (Cal. Const., art. I, § 3, subd. (b)(2)), we disagree with 
the trial court and the Court of Appeal that the ALPR scan data at issue here are 
subject to section 6254(f)’s exemption for records of investigations.  In addition, 
although we agree with the trial court that the public interest in nondisclosure of 
raw ALPR scan data clearly outweighs the public interest in disclosure of such 
data (§ 6255(a)), we remand for further consideration of whether the raw data may 
reasonably be anonymized or redacted such that the balance of interests would 
shift and disclosure of the data would be required under the CPRA.  
BACKGROUND 
The relevant facts are generally not in dispute.  The ALPR data collection 
system at issue here utilizes high-speed computer-controlled cameras mounted on 
fixed structures or on patrol cars.  The cameras automatically capture an image of 
the license plate of each vehicle that passes through their optical range.  For each 
image, the ALPR system uses character recognition software and almost instantly 
checks the license plate number against a list of license plate numbers that have 
been associated with crimes, child abduction AMBER alerts, or outstanding 
warrants.  This list of license plate numbers comprises the investigative “hot list.”  
When a hot list match occurs, the system alerts either officers in a patrol car or a 
central dispatch unit, depending on whether the ALPR unit that detects a match is 
mounted on a patrol car or a fixed structure.  Most license plate numbers that 
4 
ALPR units capture do not match the hot list and have no perceived connection to 
any crimes, AMBER alerts, or outstanding warrants.3   
The ALPR technology records each scanned license plate number, together 
with the date, time, and location of the scan, and stores the data on confidential 
computer networks.  LAPD estimates that it records data from 1.2 million cars per 
week.  It retains license plate scan data for five years.  LASD estimates that it 
records between 1.7 and 1.8 million license plates per week.  It retains scan data 
for two years.  When new investigations arise, real parties query their stored 
databases to obtain any available location history of relevant vehicles.  Both the 
LAPD and LASD restrict database access to law enforcement.   
On August 30 and September 4, 2012, petitioners sent substantially 
identical requests under the CPRA to each of the real parties, seeking “records 
related to those agencies’ use of ALPR technology, including ‘all ALPR data 
collected or generated’ during a one-week period in August 2012, consisting of, 
‘at a minimum, the license plate number, date, time, and location information of 
each license plate recorded.’ ”  Real parties withheld the requested plate scan data, 
citing the exemption for law enforcement records of investigations under section 
6254(f).  Petitioners did not seek disclosure of the hot list itself or records of which 
license plate numbers matched the hot list.   
Petitioners’ CPRA request also sought disclosure of “any policies, 
guidelines, training manuals and/or instructions on the use of ALPR technology 
and the use and retention of ALPR data, including records on where the data is 
stored, how long it is stored, who has access to the data, and how long they access 
the data.”  Real parties agreed to produce these records.   
                                              
3  
According to petitioners, “Typically, only about 0.2% of plate scans are 
connected to suspected crimes or vehicle registration.” 
5 
On May 6, 2013, petitioners filed a petition for writ of mandate in the Los 
Angeles County Superior Court to compel disclosure of the requested ALPR data.  
In opposing the petition, real parties cited the exemption for records of 
investigation under section 6254(f) as well as the catchall public interest 
exemption under section 6255(a).  After a hearing, the superior court 
acknowledged the intrusive nature of license plate scanning as well as its potential 
for abuse.  The court concluded, however, that all of the requested data were 
exempt from disclosure under both sections 6254(f) and 6255(a).    
Petitioners sought issuance of an extraordinary writ in the Court of Appeal.  
After conducting a de novo review (§ 6259, subd. (c)), the Court of Appeal 
affirmed the trial court’s judgment, holding all data exempt from disclosure under 
section 6254(f).  The Court of Appeal did not discuss either section 6255(a)’s 
balancing test or that statute’s potential application to any of the scan data.   
DISCUSSION 
1.  The CPRA 
The Legislature enacted the CPRA in 1968.  (Stats. 1968, ch. 1473, § 39, p. 
2964.)  It was modeled after the 1967 federal Freedom of Information Act (5 
U.S.C. § 552).  (Los Angeles County Bd. of Supervisors v. Superior Court (2016) 2 
Cal.5th 282, 290.)  The CPRA explains that “access to information concerning the 
conduct of the people’s business is a fundamental and necessary right of every 
person in this state.”  (§ 6250.)  To promote this fundamental right, the CPRA 
provides that “every person has a right to inspect any public record, except as 
hereafter provided.”  (§ 6253, subd. (a).)  “In other words, all public records are 
subject to disclosure unless the Legislature has expressly provided to the 
contrary.”  (Williams v. Superior Court (1993) 5 Cal.4th 337, 346 (Williams).)   
Proposition 59, a measure submitted to the voters in 2004, enshrined the 
CPRA’s right of access in the state Constitution:  “The people have the right of 
6 
access to information concerning the conduct of the people’s business, and, 
therefore, the meetings of public bodies and the writings of public officials and 
agencies shall be open to public scrutiny.”  (Cal. Const., art. I, § 3, subd. (b)(1), 
added by Prop. 59, approved by voters, Gen. Elec. (Nov. 2, 2004).)  The state 
Constitution implemented this right of access with the general directive that a 
“statute, court rule, or other authority . . . shall be broadly construed if it furthers 
the people’s right of access, and narrowly construed if it limits the right of access.”  
(Cal. Const., art. I, § 3, subd. (b)(2).)  Although the CPRA provides for a broad 
right of access, it “recognizes that certain records should not, for reasons of 
privacy, safety, and efficient governmental operation, be made public”—including 
certain records of investigations exempted under section 6254(f).  (Haynie v. 
Superior Court (2001) 26 Cal.4th 1061, 1064 (Haynie).)  We turn first to the scope 
of that exemption.     
2.  Application of section 6254(f) 
Section 6254(f) exempts from mandatory disclosure certain “[r]ecords 
of . . . investigations conducted by, or records of intelligence information or 
security procedures of, . . . any state or local police agency,” as well as certain 
“investigatory or security files.”  (§ 6254(f).)  This case requires us to construe the 
exemption for records of investigations, rather than investigatory files (Williams, 
supra, 5 Cal.4th at p. 341) or intelligence information (American Civil Liberties 
Union Foundation v. Deukmejian (1982) 32 Cal.3d 440, 443 (Deukmejian)).   
Our interpretation of the phrase “[r]ecords of . . . investigations” is guided 
by familiar principles of statutory interpretation, as well the “constitutional 
imperative” to construe CPRA in a manner that furthers disclosure.  (City of San 
Jose v. Superior Court (2017) 2 Cal.5th 608, 616–617 (City of San Jose); see 
Sierra Club v. Superior Court (2013) 57 Cal.4th 157, 166.)  The parties point us 
toward various dictionary definitions that they believe advance their positions.  
7 
Real parties observe, for example, that Black’s Law Dictionary defines the term 
“investigate” to mean “[t]o inquire into (a matter) systematically” or “[t]o make an 
official inquiry.”  (Black’s Law Dict. (9th ed. 2009), p. 902.)  This definition and 
the others suggested are not specific to the law enforcement or CPRA contexts, 
however, and afford us only minimal guidance about the meaning of the statutory 
text.  It is enough to say that the definitions of which we are aware do not compel 
(or even strongly suggest) an answer to the question before us.  A closer 
examination of the CPRA’s context, including the presumption in favor of access, 
is required.  
We previously construed the records of investigations exemption in Haynie, 
supra, 26 Cal.4th 1061.  Elgin Haynie claimed that he was injured by a Los 
Angeles County Deputy Sherriff during a traffic stop and sought certain public 
records regarding the incident.  (Id. at p. 1065.)  The sheriff’s department refused 
to provide those records, instead disclosing a “ ‘summary of the event,’ ” which 
asserted that the Deputy “ ‘received a call from a neighbor who saw several males 
carrying guns enter an older model dark blue Ford van and travel down the road. 
The deputy spotted a vehicle matching that description five minutes later and he 
decided to conduct an investigation of the van.’ ”  (Id. at pp. 1065–1066.)  The 
department asserted that the “[r]ecords of . . . investigations” exemption mooted 
CPRA disclosure.  (§ 6254, subd. (f).)  Among other things, Haynie responded that 
“ ‘records of investigations’ should be defined so as to exclude investigations that 
are merely ‘routine’ or ‘everyday police activity,’ such as his traffic stop.”  
(Haynie, supra, 26 Cal.4th at p. 1070.) 
We disagreed.  (See Haynie, supra, 26 Cal.4th at pp. 1070–1071.)  In doing 
so, we discussed the risk that Haynie’s proposed interpretation might pose to law 
enforcement operations.  “Complainants and other witnesses whose identities were 
disclosed might disappear or refuse to cooperate.  Suspects, who would be alerted 
8 
to the investigation, might flee or threaten witnesses.  Citizens would be reluctant 
to report suspicious activity.  Evidence might be destroyed.”  (Id., at pp. 1070–
1071.)  We also stressed, however, that “by including ‘routine’ and ‘everyday’ 
within the ambit of ‘investigations’ in section 6254(f), we [did] not mean to shield 
everything law enforcement officers do from disclosure.  [Citation.]  Often, 
officers make inquiries of citizens for purposes related to crime prevention and 
public safety that are unrelated to either civil or criminal investigations.  The 
records of investigation exempted under section 6254(f) encompass only those 
investigations undertaken for the purpose of determining whether a violation of 
law may occur or has occurred.  If a violation or potential violation is detected, the 
exemption also extends to records of investigations conducted for the purpose of 
uncovering information surrounding the commission of the violation and its 
agency.  Here, the investigation that included the decision to stop Haynie and the 
stop itself was for the purpose of discovering whether a violation of law had 
occurred and, if so, the circumstances of its commission.  Records relating to that 
investigation are exempt from disclosure by section 6254(f).”  (Haynie, supra, at 
p. 1071, italics added.) 
The facts of Haynie are quite unlike the facts here.  Haynie concerned an 
individual deputy stopping an individual driver, allegedly based on a single, close 
in time tip from a neighbor.  This case concerns the collection of enormous 
amounts of bulk data.  But Haynie at least implies that an inquiry must be 
somewhat targeted at suspected violations of law (see Haynie, supra, 26 Cal.4th at 
p. 1071) to qualify as an “investigation[]” under section 6254(f).  The mere fact of 
an inquiry is not enough.    
Our case law recognizes that the CPRA should be interpreted in light of 
modern technological realities.  (Cf. City of San Jose, supra, 2 Cal.5th at pp. 618–
619 & fn. 4.)  It is hard to imagine that the Legislature intended for the records 
9 
of investigations exemption to reach the large volume of data that plate scanners 
and other similar technologies now enable agencies to collect indiscriminately.  
Nothing in the text or structure of the statute suggests an effort to imbue the term 
with a meaning that capacious.  Indeed, section 6254(f) itself authorizes disclosure 
of certain portions of records of investigations, such as certain “names and 
addresses of persons involved in, or witnesses other than confidential informants 
to, the incident.”  (Italics added.)  This language suggests that the Legislature did 
not contemplate “investigation” of hundreds or thousands of individuals 
simultaneously—nor, more to the point, an exemption that would cover all data 
collected during such a far-reaching inquiry. 
Of course, the mere fact that the technology for such mass data collection 
was not in use when the Legislature enacted CPRA does not answer the question 
before us.  As Fourth Amendment jurisprudence illustrates, a provision can apply 
to new and perhaps unanticipated technologies when the purpose behind the 
provision will be served.  (Cf. Katz v. United States (1967) 389 U.S. 347, 353 
[wiretaps of phone booths are searches for Fourth Amendment purposes because 
they impinge on the privacy interests the amendment was designed to protect].)  
As we recognized in Haynie, however, the animating concern behind the records 
of investigations exemption appears to be that a record of investigation reveals 
(and, thus, might deter) certain choices that should be kept confidential––an 
informant’s choice to come forward, an investigator’s choice to focus on particular 
individuals, the choice of certain investigatory methods.  Such choices are far less 
likely to be revealed where, as here, data are collected en masse.  True, the 
collection of ALPR data can shed light on certain choices, for example, that data 
are being collected disproportionately in certain neighborhoods.  But this kind of 
revelation seems far less likely to compromise current or future law enforcement, 
and thus far less likely to prompt the concerns animating section 6254(f).   
10 
Not only are the concerns underlying the exemption only weakly implicated 
by the disclosure of the ALPR data, but broadly exempting the data would inflict a 
far greater blow to the public interest in disclosure than does exempting records 
concerning more traditional investigations.  For example, if all that mattered were 
whether an agency sought to collect information in connection with a crime (as 
opposed to no crime at all), real parties could reduce the hot list to a single license 
plate number, scan literally every plate in Los Angeles, and be able to assert that 
all of the data collected were exempt from CPRA disclosure as an “investigation” 
regarding that single plate.  In light of CPRA’s purpose of providing access to 
information regarding government activities, we doubt that the records 
of investigations exemption was intended to stretch that far. 
Perhaps the most critical point, however, is one that the Court of Appeal 
did not mention:  Our constitution requires that CPRA exemptions be narrowly 
construed, including the exemption for “[r]ecords of . . . investigations.”  
(§ 6254(f).)  Even before Proposition 59 was enacted, we recognized that not 
every inquiry is an “investigation” in the relevant sense.  (See Haynie, supra, 26 
Cal.4th at pp. 1070-1071.)  
Accordingly, we hold that real parties’ process of ALPR scanning does not 
produce records of investigations, because the scans are not conducted as part of a 
targeted inquiry into any particular crime or crimes.  The scans are conducted with 
an expectation that the vast majority of the data collected will prove irrelevant for 
law enforcement purposes.  We recognize that it may not always be an easy task to 
identify the line between traditional “investigation” and the sort of “bulk” 
collection at issue here.  But wherever the line may ultimately fall, it is at least 
clear that real parties’ ALPR process falls on the bulk collection side of it. 
Nor does the act of querying the database for information on particular 
vehicles transform existing ALPR scan records into exempt “[r]ecords of . . . 
11 
investigations” (§ 6254(f)).  A plate scan in itself always remains a result of bulk 
data collection, rather than a record of investigation, even if it has the potential to 
match a future search query.  The fact that a database has been searched or that a 
plate in the database has been matched in a search does not increase the concerns 
identified in Haynie with respect to disclosure of the database.  Moreover, a 
contrary rule would enable an agency to exempt such data, purportedly to advance 
some more traditional “investigation,” simply by searching the entire database. 
Therefore, the bulk collection of raw ALPR data here is not exempt from 
disclosure under section 6254(f).  We do not decide, however, whether an ALPR 
record that later becomes part of a more targeted investigation might properly be 
addressed under the investigatory file exemption (§ 6254(f)) which applies to 
certain “materials that relate to the investigation” if there is a “concrete and 
definite prospect of enforcement proceedings.”  (Williams, supra, 5 Cal.4th at p. 
362; compare Haynie, supra, 26 Cal.4th at pp. 1068-1069 [records of investigation 
exemption does not require concrete and definite prospect of enforcement].)  We 
next consider whether the ALPR raw data may be withheld under section 6255(a). 
3.  Application of section 6255(a) 
Section 6255(a)—CPRA’s catchall provision (see Los Angeles County Bd. 
of Supervisors v. Superior Court, supra, 2 Cal.5th at p. 291)—permits an agency 
to withhold a public record if the agency demonstrates “that on the facts of the 
particular case the public interest served by not disclosing the record clearly 
outweighs the public interest served by disclosure of the record.”  (§ 6255(a).)  
(See, e.g., Deukmejian, supra, 32 Cal.3d at pp. 452–454 [construing the 
application of the catchall provision].)  This “provision contemplates a case-by-
case balancing process, with the burden of proof on the proponent of 
nondisclosure to demonstrate a clear overbalance on the side of confidentiality.”  
(Michaelis, Montanari & Johnson v. Superior Court (2006) 38 Cal.4th 1065, 1071 
12 
(Michaelis).)  Whether such an overbalance exists may depend on a wide variety 
of considerations, including privacy (City of San Jose, supra, 2 Cal.5th at p. 626); 
public safety (Long Beach Police Officers Assn. v. City of Long Beach (2014) 59 
Cal.4th 59, 74 (Long Beach)); and the “expense and inconvenience involved in 
segregating nonexempt from exempt information.”  (Deukmejian, supra, 32 Cal.3d 
at pp. 452–453).  In balancing the interests for and against disclosure, we review 
the public interest factors de novo but accept the trial court’s factual findings as 
long as substantial evidence supports them.  (Michaelis, 38 Cal.4th at p. 1072; see 
CBS, Inc. v. Block (1986) 42 Cal.3d 646, 650-651 (CBS).) 
The trial court determined that the balance of interests under section 
6255(a) weighed clearly against disclosure of raw ALPR scan data.  We agree.  
The trial court further determined, however, that even anonymized or redacted 
plate scan data could be withheld.  Because the trial court erred in reaching this 
conclusion based on the present record, and because the inquiry requires additional 
factual development, we will remand for further proceedings.   
 
a.  Unaltered plate scan data 
As noted, petitioners seek disclosure of unaltered plate scan data, including, 
“ ‘at a minimum, the license plate number, date, time, and location information of 
each license plate recorded.’ ”  Petitioners contend that, among other things, these 
data could reveal whether law enforcement officers are using ALPR technology to 
target particular individuals, neighborhoods, or organizations.  The data could also 
shed light on the degree to which ALPR technology threatens individual privacy 
interests.    
The trial court carefully considered these interests.  It also recognized, 
however, that disclosing unaltered plate scan data to the public threatens 
individuals’ privacy.  ALPR data showing where a person was at a certain time 
could potentially reveal where that person lives, works, or frequently visits.  
13 
ALPR data could also be used to identify people whom the police frequently 
encounter, such as witnesses or suspects under investigation (albeit to a lesser 
extent than in the type of situation at issue in Haynie).  In short, as the trial court 
observed, “Members of the public would be justifiably concerned about LAPD or 
LASD releasing information regarding the specific locations of their vehicles on 
specific dates and times to anyone.”  Although we acknowledge that revealing raw 
ALPR data would be helpful in determining the extent to which ALPR technology 
threatens privacy, the act of revealing the data would itself jeopardize the privacy 
of everyone associated with a scanned plate.  Given that real parties each conduct 
more than one million scans per week, this threat to privacy is significant.  We 
therefore conclude that the public interest in preventing such disclosure “clearly 
outweighs the public interest served by disclosure of” these records.  (§ 6255(a).)4   
 b.  Anonymized or redacted plate scan data 
The trial court also considered whether the balance of interests at stake 
might be altered if ALPR data were anonymized:  “for example plate ‘G5123AP’ 
could have a random number ‘1111111’ assigned to it.”  The court assumed for 
argument’s sake that this possibility was “both workable and inexpensive.”  It 
rejected the possibility that anonymization of the ALPR data would alter the 
balance of interests, reasoning that anonymization “would address the individual 
privacy concerns, but it would not address the impact on law enforcement 
investigation.”  We conclude that the trial court placed too much weight on the 
                                              
4  
Recently enacted Civil Code section 1798.90.5 et seq. does not mention the 
CPRA, and we do not decide its substantive application here except to note that it 
prohibits public agencies from selling, sharing, or transferring ALPR data “except 
to another public agency, and only as otherwise permitted by law.”  (Id., 
§ 1798.90.52, subd. (a), added by Stats. 2015, ch. 532, § 3, eff. Jan. 1, 2016.)  The 
statute imposes civil fines for its violations.  (Ibid.) 
14 
mere possibility that law enforcement efforts would be frustrated.  Because this 
issue appears to require further factual development, however, we decline to 
resolve it in the first instance.   
The trial court’s concerns about interference with law enforcement were 
multifaceted.  The court initially concluded that even if ALPR data were 
anonymized before release, “[a] criminal could still use [that] data to follow law 
enforcement patrol patterns and still could locate a particular randomized plate at a 
particular location on specific days and times.”   
The trial court appears to have placed significant weight on the possibility 
that a criminal could use ALPR data to identify law enforcement patrol patterns.  
The court did so based on the declaration of LAPD Sergeant Daniel Gomez.  In 
pertinent part, Sergeant Gomez claimed that an individual requesting ALPR data 
“could use the data to try and identify patterns of a particular vehicle.”  (Italics 
added.)  However, Sergeant Gomez also seemed to cast doubt on the likelihood 
that an individual could do so successfully, explaining that “[u]nlike law 
enforcement that uses additional departmental resources to validate captured 
[A]LPR information, a private person would be basing their assumptions solely on 
the data created by the [A]LPR system . . . .”  Nevertheless, we will assume, as the 
trial court found, that a person could at least roughly infer patrol patterns from a 
week’s worth of plate scan data. 
The problem with this aspect of the trial court’s analysis is that, even 
assuming patrol patterns can be inferred from ALPR data, there is little reason to 
believe that this possibility points meaningfully toward “a clear overbalance on the 
side of confidentiality” with respect to all the records sought.  (Michaelis, supra, 
38 Cal.4th at p. 1071.)  For one thing, fixed ALPR scanners are just that—fixed—
so concerns about patrol patterns are inapplicable to the data they collect.  For 
another, the record does not appear to indicate that knowledge of where law 
15 
enforcement officers were during a particular week is a reliable guide to where 
they will be at some precise moment in the future.  The trial court did not find, for 
example, that real parties conduct law enforcement in the same way that they 
might operate a bus service—moving from point to point at particular times on 
particular days, never deviating to attend to other business or emergencies.  We 
are not aware of substantial evidence that would have supported such a finding.  
Likewise, the court did not determine how often any such routes change, nor 
whether the addition of new mobile scanners would make it challenging to infer 
that the absence of a patrol route in the past meant the absence of a patrol route in 
the future.   
The trial court’s judgment appears to rest on an additional error.  The court 
concluded that “an officer may make a hot list inquiry into the ALPR system and 
receive a hit at any time, thereby converting a non-specific scan to evidence in an 
individualized investigation.  Segregation of records in a fluid computerized 
environment is virtually impossible.”  This conclusion was also based on the 
declaration of Sergeant Gomez, who asserted that LAPD’s system “does not have 
the capability as a native function to segregate data based on specific parameters.”  
(Italics added.)  At the least, the trial court was mistaken to the extent it suggested 
that the burden of segregating records that might become exempt is relevant.  
Section 6255(a)’s balancing analysis considers the “expense and inconvenience 
involved in segregating nonexempt from exempt information.”  (Deukmejian, 
supra, 32 Cal.3d 440, 452–453.)  If a record is not presently exempt from 
disclosure, then an agency is not permitted to segregate and withhold it.  
Moreover, a plate scan does not become exempt merely because it later surfaces in 
a search of an ALPR database 
The critical point is that a court applying section 6255(a) cannot allow 
“[v]ague safety concerns” to foreclose the public’s right of access.  (Long Beach, 
16 
supra, 59 Cal.4th at p. 74; cf. CBS, supra, 42 Cal.3d at p. 652 [“A mere assertion 
of possible endangerment does not ‘clearly outweigh’ the public interest in access 
to these records.”].)  The trial court appears to have placed significant weight on 
speculative concerns about possible disclosure of mobile ALPR patrol patterns, 
without record evidence to support its conclusions.  The court erred in doing so. 
Notwithstanding our disagreement with the trial court’s reasoning, we do 
not have a sufficient factual record to determine whether section 6255(a)’s catchall 
exemption applies.  We therefore will remand for further proceedings.  On 
remand, the trial court should conduct a new balancing analysis—one that includes 
consideration of the feasibility of, and interests implicated by, methods of 
anonymization petitioners have suggested.  The trial court is free to explore other 
methods of anonymization and redaction as well. 
Petitioners have described two anonymization procedures.  The first is the 
substitution method discussed above:  replacing actual license plate numbers with 
fictional numbers.  Presumably, each plate would be assigned its own unique 
(fictional) number, because assigning a random number to each scan, even if 
multiple scans concern the same plate, would be no more informative than simply 
removing the plate numbers altogether.  In exploring this possibility, the court 
should evaluate the risk that a plate number could be inferred from a fictional 
number.  For example, if plate number “1111111” were repeatedly scanned in 
front of an office building during the day time, and an apartment building at night, 
it might be possible to infer the true owner of plate “1111111” and to track their 
other movements.  A second method would call for disclosure of two sets of 
ALPR data:  one that discloses the number of times that each license plate has 
been scanned, and another that contains only the time, date, and location of the 
scans.   
17 
With respect to the concern that patrol patterns might be discerned from the 
anonymized data, petitioners suggest different ways to redact the exact date and 
time of the scans, so that disclosed records would show a “heat map” of where 
scans were taken during the week of data petitioners seek, without revealing as 
much information about the mobile units that collected the scans or the license 
plates that were subject to them.  We note, however, as discussed above, that the 
current record provides little, if any, support for the concern that the data would 
enable private individuals to discern patrol patterns.  Without such information, it 
is difficult to see what public interest in nondisclosure could clearly outweigh the 
public interest in disclosure of this redacted information, but we leave the issue for 
the trial court to resolve.   
The anonymization and redaction methods we discuss may be more feasible 
than the trial court appeared to believe.  Petitioners contend that, even using real 
parties’ information system, it takes just “two computer clicks to export license 
plate data onto a spreadsheet or other type of document, which the parties can then 
modify.”  Accordingly, the trial court’s analysis should go beyond whether a 
method of removing exempt information is “a native function” of “[t]he system 
utilized by the LAPD.”  While real parties may not have designed their system to 
facilitate CPRA disclosure as a “native function,” randomizing license plate 
numbers or deleting columns from a spreadsheet, for example, would seem to 
impose little burden.  We leave the precise balance between effective 
anonymization and redaction and burden to the trial court on remand.  We remind 
the trial court and the parties, however, that if the anonymized or redacted data are 
ultimately released, the courts may exercise no restraint on how the data may be 
used apart from the restrictions placed on its dissemination under Civil Code 
section 1798.90.5 et seq.  (See Deukmejian, supra, 32 Cal.3d at p. 451.)   
18 
CONCLUSION 
We affirm the Court of Appeal judgment insofar as it exempted raw ALPR 
data from CPRA disclosure.  We reverse the Court of Appeal judgment insofar as 
it rendered anonymized or redacted ALPR data exempt from disclosure.  We 
remand the action to the Court of Appeal with instructions to remand the matter to 
the trial court for further proceedings under section 6255(a) that are consistent 
with this opinion.  
 
 CHIN, J. 
WE CONCUR: 
 
CANTIL-SAKAUYE, C. J. 
WERDEGAR, J. 
CORRIGAN, J. 
LIU, J. 
CUÉLLAR, J. 
KRUGER, J. 
 
 
See last page for addresses and telephone numbers for counsel who argued in Supreme Court. 
 
Name of Opinion American Civil Liberties Union Foundation of Southern California v. Superior Court 
__________________________________________________________________________________ 
 
Unpublished Opinion 
Original Appeal 
Original Proceeding 
Review Granted XXX 236 Cal.App.4th 673 
Rehearing Granted 
 
__________________________________________________________________________________ 
 
Opinion No. S227106 
Date Filed: August 31, 2017 
__________________________________________________________________________________ 
 
Court: Superior 
County: Los Angeles 
Judge: James C. Chalfant 
 
__________________________________________________________________________________ 
 
Counsel: 
 
Peter Bibring and Catherine A. Wagner for Petitioner American Civil Liberties Union Foundation of 
Southern California. 
 
Jennifer Lynch for Petitioner Electronic Frontier Foundation. 
 
Katie Townsend for the Reporters Committee for Freedom of the Press, American Society of News Editors, 
Association of Alternative Newsmedia, California Newspaper Publishers Association, Californians Aware, 
The Center for Investigative Reporting, First Amendment Coalition, Los Angeles Times Communications 
LLC, The McClatchy Company, The National Press Club, National Press Photographers Association, 
Online News Association and Society of Professional Journalists as Amici Curiae on behalf of Petitioners. 
 
First Amendment Project, James R. Wheaton and Cherokee D.M. Melton for Northern California Chapter 
of the Society of Professional Journalists as Amicus Curiae on behalf of Petitioners. 
 
Marc Rotenberg, Alan Butler, Jeramie Scott and Aimee Thomson for Electronic Privacy Information 
Center as Amicus Curiae on behalf of Petitioners. 
 
Jason D. Russell and Richard A. Schwartz for Senator Jerry Hill as Amicus Curiae on behalf of Petitioners. 
 
No appearance for Respondent. 
 
Jones & Mayer, Martin J. Mayer, James R. Touchstone and Deborah Pernice-Knefel for California State 
Sheriffs’ Association, California Police Chiefs’ Association and California Peace Officers’ Association as 
Amici Curiae on behalf of Respondent. 
 
Michael N. Feuer, City Attorney (Los Angeles), Carlos de La Guerra, Managing Assistant City Attorney, 
Debra L. Gonzales and Amy Jo Field, Assistant City Attorneys, Lisa S. Berger and Heather L. Aubry, 
Deputy City Attorneys, for Real Parties in Interest City of Los Angeles and Los Angeles Police 
Department. 
 
 
 
 
 
 
 
 
Page 2 – S227106 – counsel continued 
 
Counsel: 
 
Collins Collins Muir + Stewart, Eric Brown, Tomas A. Guterres and James C. Jardin for Real Parties in 
Interest County of Los Angeles and Los Angeles Sheriffs’ Department. 
 
Colantuono, Highsmith & Whatley, Aleksan R. Giragosian, Michael G. Colantuono and Michael R. 
Cobden for League of California Cities and California State Association of Counties as Amici Curiae on 
behalf of Real Parties in Interest. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Counsel who argued in Supreme Court (not intended for publication with opinion): 
 
Peter Bibring 
ACLU Foundation of Southern California 
1313 West Eighth Street 
Los Angeles, CA  90017 
(213) 977-5295 
 
Heather L. Aubry 
Deputy City Attorney 
200 North Main Street, Room 800 
Los Angeles, CA  90012 
(213) 978-6956 
 
James C. Jardin 
Collins Collins Muir + Stewart 
1100 El Centro Street 
South Pasadena, CA  91030 
(626) 243-1100