Under the Influence

California Health and Safety Code Section 11550 (HS 11550) makes it a misdemeanor to use or be under the influence of a controlled substance without a valid prescription. According to this law, the prosecution must prove that the controlled drug had an effect on your nervous system, brain, or muscles in any detectable way or that you knowingly used a controlled substance right before your arrest.

This charge applies anywhere, even in private homes, unlike driving charges, which apply only in public places. Conviction means time in county jail, significant fines, and personal ramifications. If facing charges for an HSC 11550 violation, hire a lawyer who understands police investigation techniques and can build solid defense strategies.

At Leah Legal Criminal Defense Attorney, we represent you in court when you face drug charges in Los Angeles. We also work to defend your case, seek diversion, or have your case dismissed.

Understanding California Health and Safety Code Section 11550 HS

California HS 11550(a) makes it a criminal misdemeanor to be under the influence of scheduled narcotics or unprescribed pharmaceuticals. The prosecutor does not have to prove you acted recklessly or drove a car. Therefore, if any amount of the prohibited substance is detected in your body, you face arrest.

The Legal Standard of “Under the Influence” in California

The prosecution does not have to prove that your physical coordination was impaired to an extent that you were stumbling or were a threat to the safety of others.

Under the legal standard established in CALCRIM No. 2400, the state only needs to prove that a controlled substance affected your nervous system, brain, or muscles in any detectable manner. The prosecution meets its burden if the evidence shows that the drug caused a noticeable mental or physical abnormal condition.

Peace officers authorized to arrest under California Penal Code Section 836 PC frequently rely on subtle physiological reactions as grounds for arrest because the arrest threshold is so low. A slight rise in your pulse, some mild hand tremors, or a slight adjustment in your pupils when you’re lit up with a penlight can cause an officer to say that you committed a crime.

This is a subjective standard, which makes these cases susceptible to overreach and provides your defense attorney with a solid foundation to assert that the evidence presented by the State is not accurate.

Controlled Substances Covered Under HS 11550

HS Sections 11550(a)(1) and (a)(2) apply to certain compounds included on Schedules I through V of the California Uniform Controlled Substances Act (HS Sections 11054 – 11058). Illicit street drugs and controlled pharmaceutical medications taken without an authorized medical prescription are illegal.

Common substances leading to prosecution under this statute include:

• HS 11054(d) and Section 11055(d) apply to illicit central nervous system stimulants like methamphetamine, amphetamine, cocaine, and cocaine base.
• Opiates and synthetic opioids, such as heroin, fentanyl, morphine, hydrocodone, and oxycodone, are regulated by HS Sections 11054(b) and (c) and Section 11055(b).
• HS 11054(d)(21)-(23) governs hallucinogens and dissociative anesthetics such as phencyclidine (PCP), ketamine, psilocybin, and lysergic acid diethylamide (LSD).
• Alprazolam, diazepam, lorazepam, and clonazepam are all prescribed central nervous system depressants and sedatives that are classified as Schedule IV controlled substances under HS 11057.

HS 11550 does not include adult-use cannabis. After Proposition 64 passed, the legal use of marijuana by adults (21+ years old) is governed by a different set of codes from the legal use of marijuana by minors (under 21 years old). It is illegal to drive while impaired by marijuana under California VC 23152(f). While you may face other penalties for using marijuana in designated non-smoking public areas, you cannot be charged with violating HS 11550 if you are only impaired by marijuana.

Recent Use vs. Past Use and Withdrawal

A prosecutor can charge you with the unlawful ‘use’ of a controlled substance under HS 11550(a) even if you are no longer actively high. When charging you with the unlawful “use” of a controlled substance under HS 11550(a), California law requires the prosecutor to prove that your use was current.

Per People v. Velasquez (1976) 54 Cal. App. 3d 695 and People v. Jones (1987) 189 Cal. App. 3d 398, “current use” requires that you have ingested the substance immediately before your arrest. The facts determine the time frame in each case at trial.

Still, California courts have adopted the guideline that consumption within 48 hours to five days before police contact may be considered in assessing a conviction. For current use, the state cannot convict you if your last use was several weeks ago.

Moreover, it is not a crime to suffer from drug withdrawal. People v. Gutierrez (1977) 72 Cal.App.3d 397 provided that suffering from withdrawal symptoms demonstrates past drug use rather than active, present intoxication. If you show signs of physical distress due to the withdrawal of a narcotic from your body, the prosecution cannot prove that the narcotic is having a significant effect on the central nervous system in the manner prohibited by HS 11550.

How Law Enforcement Investigates HS 11550 Allegations

Police use physical observations and chemical tests to build a case against you. However, their methods are often flawed. Your defense attorney can expose these mistakes to throw out the evidence.

Drug Recognition Expert (DRE) 12 Step Impairment Protocols

Patrol officers frequently call a Drug Recognition Expert (DRE) when they suspect drug intoxication. DRE officers undergo specialized training under the direction of the International Association of Chiefs of Police (IACP) to detect physical indicators of seven drug categories.

The following is the standardized 12-step DRE protocol:

1. Administering a breath alcohol test to rule out alcohol as the sole cause of impairment
2. Initial interview with the arresting officer about what they saw
3. Your initial physical exam, including pulse checks
4. Assessment of horizontal gaze nystagmus, vertical gaze nystagmus, and lack of convergence on eye examination
5. Divided attention psychophysical tests, like Romberg balance, walk-and-turn, and finger-to-nose
6. Vital signs examination, which includes blood pressure, body temperature, and pulse rate
7. Three different light conditions for darkroom pupil examinations
8. Evaluation of muscle tone, such as flaccidity and rigidity
9. Examination of injection sites, track marks, and nose passages
10. Interrogation about your drug use
11. Establishment of the DRE’s diagnostic opinion
12. Taking a biological chemical sample, like blood or urine

While law enforcement generally presents DRE testimony as a science, it remains a subjective evaluation. Cold temperatures, flashing emergency cruiser lights, street dust, and stress can result in abnormal pupil dilation, an elevated pulse, or poor balance on uneven pavement. An officer’s failure to follow the IACP 12-step protocol diminishes the prosecution’s case before a jury.

Vulnerabilities of Blood and Urine Chemical Testing

In court, toxicology reports are generally considered conclusive proof, but chemical and biological testing have significant scientific and procedural weaknesses.

Common problems with chemical testing include:

• Identifying inactive, past drug metabolites from active, impairing ones
• The improper collection, refrigeration and biological sample preservation under California Code of Regulations Title 17
• Crime lab instrument drift and known false-positive rates
• Failure to maintain a chain of custody record by the technicians

Urine immunoassay screening can detect metabolic byproducts that persist in fatty tissue for days or weeks after the psychoactive effect wears off. If you test positive for cocaine or methamphetamine metabolites in a urine test, it means that you were exposed to these drugs at some point in your life, but not necessarily at the time of your arrest.

Penalties and Long-Term Consequences of an HS 11550 Conviction

If you are convicted of an HS 11550 misdemeanor, you face harsh statutory penalties, including mandatory custody. In addition to court penalties, a drug conviction carries collateral consequences that affect one’s ability to obtain employment, professional licenses, firearm privileges, immigration status, and more; therefore, strong legal intervention is required from the beginning.

The 90-Day Mandatory Jail Provision and Misdemeanor Sentencing Terms

California HS 11550(a) classifies a conviction as a misdemeanor punishable by up to 1 year in jail. Subdivision (a) includes a mandatory statutory sentence of at least 90 days in prison, in contrast to the common practice among California judges of suspending jail time for most misdemeanor offenses.

If you’ve had two prior HS 11550(a) convictions within the last seven years of a violation of subdivision (a) of HS 11550 and still choose not to comply with the court’s order, the law requires that you serve at least 180 days in county jail. This subdivision prohibits the sentencing judge from dismissing this 180-day jail sentence unless there are no reasonably available licensed rehabilitation facilities.

Aggravating Enhancements

If a gun is involved in the alleged incident, penalties increase significantly. California HS 11550(e)(1) provides a specific felony-misdemeanor “wobbler” enhancement for carrying a loaded, operable firearm while under the immediate, personal possession of cocaine, cocaine base, heroin, methamphetamine, or phencyclidine (PCP).

The term “immediate personal possession” under HS 11550(e)(2) shall mean having the weapon on your person or in the interior passenger compartment of a motor vehicle. If the defendant is convicted of a felony under subdivision (e), they are prohibited from possessing a firearm for life pursuant to California PC 29800(a)(1).

Collateral Professional, Immigration, and Personal Repercussions

The penalties for a misdemeanor drug charge are not limited to court and can affect many aspects of life:

• Professional Licensing Sanctions — The Medical Board of California, the California Board of Registered Nursing, the State Bar, and the Department of Real Estate are among the state licensing boards that consider controlled-substance convictions to be examples of unprofessional conduct by their members. The conviction may lead to a formal investigation, the suspension of a license, or participation in an expensive monitoring program.
• Adverse Immigration Consequences — The Immigration and Nationality Act makes any non-citizen who commits a controlled substance violation, except for a single offense of possession of 30 grams or less of marijuana, deportable and inadmissible. This federal requirement will impact lawful permanent residents (green card holders), DACA recipients, and temporary visa holders.
• Commercial and Personal Housing Barriers — Denial of housing applications by landlords and property management companies is commonplace, particularly for people who have a current or past drug conviction on their record.

California Drug Diversion Programs

Under PCs 1000 and 1210.1, specific statutory provisions offer alternative pathways to replace incarceration for non-violent drug crimes with rehabilitation. If you are eligible and admitted to these programs, you can receive education or counseling, which eliminates the requirement for a jail sentence and dismisses the underlying misdemeanor charge.

Pre-Trial Diversion (PC 1000)

California PC 1000 provides pre-trial diversion as an option for you if you are facing charges for simple drug crimes to avoid a criminal record. After significant statutory revisions, PC 1000 is now a genuine pre-guilty-plea program and no longer requires the entry of a plea of guilty or no contest.

To be eligible for pre-trial diversion under California PC 1000(a):

• The current charge must be a simple use, possession, or being under the influence charge
• Must not have convictions for any disqualifying offense (other than a disqualifying offense of a qualifying nature) in the last 5 years
• No violence, threats of violence, or simultaneous narcotics sales allegations are to be charged

During the program, which usually lasts anywhere from six to 12 months, you engage in court-ordered substance abuse education, regular check-ins, and drug testing. If the judge finds that you have completed the program, they will dismiss the charge entirely pursuant to California PC 1000.3.

Proposition 36 (PC 1210.1)

California PC 1210.1 (Proposition 36) offers an alternative treatment option if you require a structured probation.

Proposition 36 differs from pre-trial diversion in that it requires entering a formal plea of guilty or no contest. The court sentences you, but then suspends the sentence, and instead imposes a condition of up to 1 to 2 years of licensed outpatient or residential substance abuse treatment.

Once the court-ordered treatment program is completed and all conditions of probation are met, the underlying conviction is dismissed under California PC 1210.1(e)(1). Failure to comply and/or new criminal charges may result in the revocation of probation and the imposition of the statutory 90-day jail sentence.

Strategic Legal Defenses Against HS 11550 HS Charges

An HS 11550 allegation must be met by identifying constitutional issues, scientific misunderstandings, and factual inconsistencies in the state’s evidence. A custom defense will question illegal detentions, establish legal drug use, or establish other medical causes that will break the prosecutor’s case before or at trial.

Valid Medical Prescription Defense

The law does not apply if the controlled substance was administered by or taken under the direction of a licensed physician, dentist, podiatrist, or veterinarian authorized to prescribe medicine, as provided by the express statutory exception contained in HS 11550(a).

If a licensed doctor prescribed your medication and you used it exactly as prescribed, then you did not break any law. While subdivision (a) requires the defense to present evidence of the prescription, the defense’s production of certified logs from the pharmacy that dispensed the prescription and records from the prescribing physician is sufficient to create a complete defense, and the prosecutor must drop the charges.

Involuntary Intoxication and Lack of Willful Consumption

Under HS 11550, a person is criminally liable for consuming a controlled substance if the person does so with the intent to do so. PC 7(1) and CALCRIM No. 2400 require that an act be committed with the intent or purpose of committing it.

Your lawyer can secure surveillance video from the bar or restaurant, gather eyewitness accounts of your abrupt change of behavior, and present forensic timelines that demonstrate you had no knowledge that you were taking a drug. Pursuant to PC 7(1) and CALCRIM No. 2400, the absence of willful ingestion eliminates criminal intent.

Fourth Amendment Violations and PC 1538.5 Motions to Suppress Evidence

The Fourth Amendment of the U.S. Constitution protects you from unreasonable searches and seizures. Police officers may not stop, detain, or search you without reasonable suspicion of criminal activity; arrest you; or seize biological fluid samples without probable cause.

All evidence the officer obtained after the stop is tainted if they stopped your car or detained you on the street without reasonable suspicion. Your defense attorney can file a motion to suppress evidence in California PC 1538.5.

Medical Conditions Mimicking Intoxication Symptoms

Police officers frequently misinterpret physical conditions, chronic illnesses, or acute medical emergencies as evidence of the influence of illegal drugs. Numerous physiologic states present with similar signs and symptoms to narcotics.

Physical/medical explanations that parallel drug intoxication include:

• Diabetic ketoacidosis (DKA) causes drowsiness, confusion, and physical unsteadiness
• Excessive tiredness, inability to sleep, or stress leading to dilated pupils and bloodshot eyes
• Neurological conditions that affect balance, movement, and eye convergence.
• An abnormal reaction to light due to infection, allergies, or trauma to the eye.

Submitting a medical history, doctor’s evaluations, and testimony from an experienced medical professional can help demonstrate that your appearance was due to a medical condition, not to the illegal use of a controlled substance.

Related  California Drug and Alcohol Crimes

In addition to HS 11550 charges, prosecutors often charge related statutory violations based on the circumstances and evidence they discover during an arrest. Understanding the overlap among these statutes can help defense counsel negotiate and challenge duplicative charges and pursue reduced or drug-free dispositions.

California HS 11350, Possession of a Controlled Substance

California HS 11350(a) makes it a misdemeanor to possess controlled substances without a prescription. Police officers are trained to search a person’s person and immediate environment when they are suspected of being intoxicated. When officers discover a baggie with residue or unused narcotics, prosecutors usually charge you with possession (HS 11350) and possession with the intent to distribute (HS 11351).

Being under the influence is when the drug is in your body; possession is when you have it in your pocket or in your car. With good legal representation, prosecutors won’t be able to force an unfair plea deal through duplicative charges.

California HS 11364, Possession of Drug Paraphernalia

California HS 11364(a) makes it a misdemeanor to possess any device, pipe, hypodermic needle, or instrument for unlawfully injecting, smoking, or consuming a controlled substance.

Smoking pipes, burnt spoons, and syringes are often found in the possession of someone arrested for HS 11550 and are considered paraphernalia. Convictions for HS 11364 are punishable by up to six months in county jail. Paraphernalia charges (HS 11364), much like under the influence charges (HS 11550), are typically eligible for alternative resolution through PC 1000 diversion.

California Vehicle Code 23152(f), DUI-Drugs

If an officer sees you driving a motor vehicle before he or she tests you for drug use, prosecutors will charge you with DUID (California VC 23152(f)) in addition to or in place of HS 11550.

California VC 23152(f) requires proving that your physical or mental state is impaired. Your mental condition was so impaired that you were no longer able to operate a vehicle with the caution of a sober driver using ordinary care, unlike HS 11550, which only requires that a drug be detected in your body.

In California, DUID convictions result in driver’s license suspension through the California DMV per the California VC 13352, mandatory DUI school, and increased monetary fines.

California Penal Code 647(f) PC (Public Intoxication)

California PC 647(f) makes it a misdemeanor to be intoxicated with drugs, alcohol, or toluene in a public place. Under PC 647(f), however, the standard for the prosecution is much more stringent than HS 11550.

California PC 647(f) requires the state to prove:

• You were in a public location voluntarily.
• You were intoxicated to the extent that you were unable to be careful for your own safety or the safety of others, or you interfered with a public street, sidewalk, or passageway.

PC 647(f) is not applicable if you were in a private house, hotel room, or backyard. On the other hand, HS 11550 applies in both public and private areas if the police have lawful entry.

Expunging an HS 11550 Record Under PC 1203.4

A prior conviction under HS 11550 does not mean it is on your record permanently. California law offers a straightforward legal path to remove a criminal record and the professional consequences that come with it.

California PC 1203.4(a) allows you, as a convicted misdemeanant, to petition the Superior Court for an expungement. If granted, the judge will set aside the prior guilty or no-contest plea, enter a not-guilty plea, and dismiss the charge. While clearing your record under PC 1203.4 removes many private employment barriers, it does not completely erase the event. You must still disclose the conviction when applying for state professional licenses, and it can still trigger severe federal immigration consequences.

Find an Experienced Criminal Defense Lawyer Near Me

An arrest for violation of California Health and Safety Code 11550 puts your personal freedom, career, and criminal record at risk. Time is critical to preserve critical evidence, contest chemical test results, and determine eligibility for state drug diversion programs such as Penal Code 1000.

At Leah Legal Criminal Defense Attorney, we have defended many suspects against misdemeanor and felony drug charges in Los Angeles. We review police behavior, file strong suppression motions, and pursue every option to have your charges dropped or reduced. You can speak to us for free at 213-444-7818, on a confidential basis, at zero cost, to discuss your defense options and begin developing a strong defense strategy.