Oxnard Police Department DUI Checkpoint Successfully Challenged
Note: This article is for information purposes only. It does not constitute legal advice. You should contact a competent criminal defense attorney following any arrest for a criminal offense.
Attorneys William Haney* and Brian Weilbacher successfully challenged a DUI checkpoint established by the Oxnard Police Department. Officers constructed the checkpoint on Oxnard Boulevard in the vicinity of a shopping center containing BJ’s Restaurant and Brewhouse, and other businesses. A Ventura County judge found that Oxnard police officials failed to follow constitutional guidelines for establishing the disputed checkpoint. The court suppressed all evidence derived from the checkpoint and dismissed the defendant’s misdemeanor DUI case on October 15, 2019.
DUI Checkpoint Factors Considered by Courts
The Ventura County Superior Court judge underscored that his ruling was not a criticism of law enforcement’s use of DUI checkpoints. To the contrary, California courts recognize that “deterring drunk driving and identifying and removing drunk drivers from the roadways undeniably serves a highly important governmental interest.”1 Police agencies must follow guidelines established by the California Supreme Court in 1987 to utilize DUI checkpoints in their effort to curb drunk driving.2
Lower courts look to eight factors established by the Supreme Court when deciding whether a checkpoint passes constitutional muster. The eight criteria are often referred to as the “Ingersoll factors”:
(1) The decision to establish the DUI checkpoint, site selection, and operating procedures must be established by supervisory personnel.3
In one California case, a court declared a DUI checkpoint invalid where a sergeant implemented the agency’s field procedures.4 Courts want to ensure that policymakers make the critical decision to block roadways and subject motorists to surprise encounters with police officers. In several cases, a Sheriff, a commander of a traffic enforcement division, and a police chief, were all deemed to be command-level personnel.5 A law enforcement officer ranking at the captain-level or higher would likely meet the court’s definition of “command-level” personnel.6
(2) Police personnel must stop motorists according to a neutral formula.7
Officers must operate by a formula designed to limit their discretion in the field. Officers may choose to stop all vehicles or any number of vehicles based on a pre-planned formula. Screening procedures may also be altered in a manner consistent with traffic volume.8
(3) Police personnel must take adequate safety precautions, and utilize proper lighting, warning signs, signals, and officially marked personnel and vehicles.
(4) The policy-making official must make a reasonable determination when selecting the site of the checkpoint.9
The policymaker must select the checkpoint in a manner that serves the governmental interest of reducing alcohol-related death and injury. Accordingly, the location must demonstrate a high incidence of alcohol-related accidents and/or arrests. Safety factors must also be considered in choosing the appropriate location.10
(5) The time and duration of the DUI checkpoint must reflect “good judgment” on the part of law enforcement officials.11
(6) The DUI checkpoint must exhibit sufficient indicia of its official nature.12
(7) Officers operating the DUI checkpoint must minimize the average length and nature of each motorist’s detention.13
In Ingersoll, motorists were detained 28 seconds on average. Detentions averaged six minutes in length for those motorists given sobriety tests.14 The Supreme Court stated, “No hard and fast rules as to timing or duration can be laid down, but law enforcement officials will be expected to exercise good judgment in setting times and durations, with an eye to the effectiveness of the operation. . .”15
(8) The DUI checkpoint must be preceded by publicity.16
“Advanced publicity is important to the maintenance of a constitutionally permissible sobriety checkpoint. Publicity both reduces the intrusiveness of the stop and increases the deterrent effect of the roadblock.”17
A lack of advanced publicity alone will not render a DUI checkpoint unconstitutional. If other failures also exist, however, the lack of advanced publicity can render the sobriety checkpoint to be unreasonable.18
Courts appear to recognize that checkpoints more meaningfully serve the governmental interest of deterring drunk driving if they are publicized in advance. Stepped up DUI enforcement offers little impact on impaired driving without advanced publicity.19 The goal of the checkpoint is not to arrest a few impaired motorists on a given night, but to deter a greater number of people from chancing fate on the roadway.
Flaws found in the Oxnard Police Department’s DUI Checkpoint
The Ventura County Superior Court found that the checkpoint established by Oxnard Police Department personnel in January 2018 failed to meet constitutional standards.
A senior officer prepared a press release the night before the checkpoint was to occur. The document lacked the location of the checkpoint. During the suppression hearing, prosecutors were unable to elicit testimony from police personnel that established any advanced media coverage of the checkpoint. The officer in charge could only point to his department’s Facebook page to demonstrate that any advanced publication of the checkpoint occurred. The court found that the government failed to establish the advanced-publicity prong of the Ingersoll requirements.
Based on the prosecution’s record, the court found that command-level personnel were not involved in the decision to conduct a checkpoint on Oxnard Boulevard. The department delegated this authority to two traffic sergeants. The court could find no involvement of policy-making officials in any of the essential aspects of the operation of the checkpoint. While noting the importance of DUI checkpoints to public safety, the court was left with no choice but to deem the roadblock unconstitutional.20
A police department news release later indicated that the unconstitutional checkpoint resulted in four DUI arrests and 737 drivers screened. (see here)
How to Challenge a Checkpoint in Court
Experienced lawyers know that DUI checkpoints are extremely difficult to successfully challenge on Fourth Amendment grounds. Courts underscore that appropriately designed DUI checkpoints save lives and serve the public’s interest. Courts look at the Ingersoll factors in their entirety when balancing the reasonableness of a checkpoint, so one or more failures may not be fatal. Most importantly, police agencies typically receive detailed input from local prosecutors concerning how to correctly conduct DUI checkpoints. It is also common for prosecutors to monitor checkpoints and to provide advice and consultation on scene.
Practically speaking, defense attorneys are typically “playing for the fumble” when challenging a DUI checkpoint. Successful challenges are generally attributed to one of several failures: (a) the prosecutor shows up unprepared at a suppression hearing to demonstrate agency compliance with the Ingersoll factors; or (b) the police agency becomes lax in the implementation of its policies and procedures due to long-standing successes.
A criminal defense lawyer should discuss the circumstances of the checkpoint with his/her client, and those factors surrounding the arrest. It is recommended that counsel obtain the “checkpoint packet” setting forth the agency’s attempts to comply with the Ingersoll factors. Checkpoint packets typically contain the agency’s press release, statistics underlying site selection, and other items relevant to the Ingersoll factors.
Attorneys routinely visit the location, examine areal maps, and obtain officers’ body-worn camera footage to further evaluate the validity of the checkpoint. California Drunk Driving Law by Paul Berglin, Barry Simons and Ed Kuwatch, contains excellent advice concerning the evaluation of DUI checkpoint cases.21
DUI Checkpoint Sources Cited:
*About the Author: Attorney William Haney served as a Ventura County deputy district attorney for 17 years. Mr. Haney is the former supervising prosecutor overseeing all alcohol-related misdemeanor and felony cases. 
1. People v. Banks (1993) 6 Cal.4th 926.
2. Ingersoll v. Palmer (1987) 43 Cal.3d 1321. The court viewed DUI checkpoints to be analogous to regulatory searches conducted on departing airport passengers.
3. People v. Banks (1993) 6 Cal.4th 926; see also People v. Alvarado (2011) 193 Cal.App.4th Supp. 13.
4. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13, 17. Attorneys Haney and Weilbacher elicited testimony from witnesses in the Ventura County hearing that a sergeant was the highest-ranking officer involved in the Oxnard Boulevard checkpoint.
5. Ingersoll v. Palmer (1987) 43 Cal.3d 1321.
6. See People v. Alvarado (2011) 193 Cal.App.4th Supp. 13 [on-scene sergeant deviated from protocols and procedures established by his captain]
7. Ingersoll v. Palmer (1987) 43 Cal.3d 1321.
8. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13, 17.
9. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13, 18.
10. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13, 18.
11. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13, 18.
12. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13.
13. People v. Alvarado (2011) 193 Cal.app.4th Supp. 13.
14. Ingersoll v. Palmer (1987) 43 Cal.3d 1321, 1327.
15. Ingersoll v. Palmer (1987) 43 Cal.3d 1321, 1327; see also People v. Alvarado (2011) 193 Cal.app.4th Supp. 13, 19.
16. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13, 19.
17. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13, 19 [citing Ingersoll at 1299].
18. People v. Alvarado (2011) 193 Cal.App.4th Supp. 13, 19
19. Ingersoll v. Palmer (1987) 43 Cal.3d 1321, 1340.
20. The court noted that the sergeants administering the checkpoint executed their duties on-scene in a safe and constitutionally authorized manner. They limited the discretion of junior officers in the field. They established safe conditions and a neutral detention formula. The checkpoint was appropriately marked with signs and official police personnel. Additionally, motorists were detained for only nine seconds on average. The checkpoint failed Ingersoll scrutiny due to the lack of advanced publicity and the agency’s reliance on police officers below the policymaking level to determine where to set up, and how to implement the checkpoint.
21. The Ventura County Law Library located at 800 South Victoria Avenue, Ventura, possesses a publicly-available copy for review and checkout. Library personnel may be reached at (805) 642-8982 to verify the present availability of the treatise. California Drunk Driving Law may be purchased through Amazon (link) or through James Publishing (link).
