In law, “PC” most commonly stands for probable cause, penal code, or professional corporation. It can also mean per curiam, privileged communication, or protective custody depending on where you encounter it. A police affidavit uses it one way, a criminal statute another, and a law firm’s letterhead a third. Context decides which meaning applies.
Probable Cause
Probable cause is the legal standard that keeps law enforcement from searching your property or arresting you on a hunch. Officers need a reasonable basis, grounded in actual facts, to believe a crime has occurred and that you or a specific location is connected to it. The Fourth Amendment builds this requirement directly into the warrant process: no warrant can issue without probable cause, supported by sworn statements, that specifically describes the place to be searched and the items to be seized.1Congress.gov. U.S. Constitution – Fourth Amendment
A judge or magistrate decides whether the evidence officers present crosses that threshold. The standard isn’t certainty. Courts describe it as a “fair probability” that evidence of a crime will turn up in a particular place or that a suspect was involved in criminal activity. In Illinois v. Gates (1983), the Supreme Court adopted a “totality of the circumstances” approach, letting judges weigh all available information together rather than checking boxes on a formula.2Justia U.S. Supreme Court Center. Illinois v. Gates, 462 U.S. 213
Officers can build probable cause from eyewitness accounts, informant tips, physical evidence, or surveillance. The reliability of those sources matters. An officer still must explain specific, articulable facts supporting the belief that a crime occurred; vague suspicion or generalized hunches don’t qualify.
When officers get it wrong, the consequences for a prosecution can be severe. In Mapp v. Ohio (1961), the Supreme Court held that evidence obtained through unconstitutional searches is inadmissible in state courts.3Justia. Mapp v. Ohio, 367 U.S. 643 If a defense attorney successfully argues that officers lacked probable cause for a search or arrest, the evidence collected can be thrown out entirely.
Penal Code
When you see “PC” followed by a section number in a criminal case, it almost always refers to a penal code. A penal code is the body of statutes that defines criminal offenses and sets out their punishments within a jurisdiction. Every state has its own version, and the specific section numbers vary. California’s Penal Code Section 187 defines murder, which is why “PC 187” has become shorthand even in popular culture.
Penal codes are the backbone of criminal law practice. Prosecutors use them to determine what charges fit the facts, defense attorneys use them to identify the elements the state must prove, and judges rely on them for sentencing ranges and jury instructions. A penal code section typically spells out exactly what conduct is prohibited, what mental state the defendant must have had, and what penalties apply.
These codes aren’t static. Legislatures regularly amend them. Offenses that once carried mandatory prison time may be reclassified as misdemeanors, and conduct that wasn’t previously criminal can be added. If you’re looking up a specific section, verify you’re reading the current version, since older editions may list penalties or definitions that have since changed.
One distinction matters when reading case documents: a penal code covers the substantive law (what counts as a crime and what happens if you’re convicted), while a separate code of criminal procedure typically governs the process. Both may be abbreviated in ways that include “PC,” so context still counts.
Professional Corporation
In business and legal practice, “PC” after a firm name stands for professional corporation. This is a corporate structure designed specifically for licensed professionals such as lawyers, doctors, accountants, and architects. The defining feature is that shareholders generally must hold a license in the same profession the corporation practices, which keeps decision-making in the hands of people bound by the field’s ethical rules.
The liability picture is more nuanced than it looks at first glance. The corporate structure shields individual shareholders from the business debts of the corporation and from malpractice claims against other shareholders. But each professional remains personally on the hook for their own negligence or malpractice. If a lawyer in a PC commits malpractice, the other shareholders’ personal assets are generally protected, but the lawyer who made the mistake can’t hide behind the corporate form.
A professional corporation is taxed as a regular C corporation by default, with a flat 21% corporate tax rate on taxable income. The IRS classifies many professional corporations as “personal service corporations” when their principal activity involves fields like law, health, accounting, engineering, architecture, consulting, or the performing arts, and when employee-owners substantially perform those services and own more than 10% of the corporation’s stock.4Internal Revenue Service. Publication 542 – Corporations
Per Curiam
“Per curiam” is Latin for “by the court.” When a court issues a per curiam opinion, the decision is attributed to the court as a whole rather than to any individual judge. You won’t see a specific justice’s name at the top. These opinions tend to be shorter and are often used when the court considers the legal question straightforward or wants to present a unified front.
Per curiam decisions appear at every level of the federal court system, including the Supreme Court. Most are routine, but some have been landmark rulings. Bush v. Gore (2000), which effectively decided a presidential election by halting Florida’s manual recount on equal protection grounds, was issued as a per curiam opinion.5Justia U.S. Supreme Court Center. Bush v. Gore, 531 U.S. 98 The fact that a decision is per curiam says nothing about its importance or controversy. Individual justices can still file concurrences or dissents.
Privileged Communication
In some legal contexts, “PC” refers to privileged communication. This is the doctrine that protects certain confidential conversations from being forced into the open during court proceedings. Some relationships require candor to function, and people won’t speak honestly with their lawyer, doctor, or clergy member if those conversations can be subpoenaed.
In federal courts, privilege is governed by common law as interpreted by the courts, unless the Constitution, a federal statute, or Supreme Court rules say otherwise. In civil cases where state law supplies the rule of decision, state privilege law applies.6Legal Information Institute. Federal Rules of Evidence – Rule 501 Privilege in General The most commonly recognized categories include attorney-client privilege, doctor-patient privilege, clergy-penitent privilege, and marital privilege.
Attorney-client privilege is the one people encounter most often. It protects confidential communications between a client and their lawyer made for the purpose of obtaining legal advice. The privilege belongs to the client, not the attorney, meaning only the client can waive it. One important wrinkle: the privilege requires actual confidentiality. If a third party who isn’t necessary for the legal representation is present during the conversation, the privilege may be destroyed. Courts recognize exceptions for people whose presence is essential, like translators, paralegals, or experts the attorney needs to consult, but bringing a friend or family member along to a meeting with your lawyer is risky.
Marital privilege actually encompasses two separate protections. The marital communications privilege covers private statements made between spouses during the marriage and can survive divorce or the death of a spouse. Spousal testimonial privilege, which applies only in criminal cases, allows a witness-spouse to refuse to testify against the other spouse. Testimonial privilege expires when the marriage ends, but it covers events that happened before the marriage as well.7Legal Information Institute. Marital Privilege
No privilege is absolute. The most significant exception is the crime-fraud exception, which strips the protection from communications made to further an ongoing or future crime or fraud. A client who tells their lawyer about a past crime is protected; a client who asks their lawyer for help committing one is not.
Protective Custody
“PC” can also stand for protective custody, meaning the confinement of a person when authorities believe it’s necessary to shield them from an immediate threat to their safety. Unlike an arrest, protective custody is justified by a protective purpose rather than as punishment, and it can be voluntary or involuntary.8Legal Information Institute. Protective Custody The term shows up in domestic violence situations, child welfare cases, and within correctional facilities when an inmate faces threats from other prisoners. In prison contexts especially, “PC” as protective custody appears frequently in inmate records and facility documentation.
How to Tell Which PC You’re Looking At
The meaning almost always follows from the document. In a police report, affidavit, or motion to suppress, “PC” is probable cause. Next to a number in a criminal charging document, it’s a penal code section. After a firm or practice name on a business card, letterhead, or court filing signature block, it’s a professional corporation. At the top of a court opinion in place of an author’s name, it’s per curiam. In evidentiary disputes and discovery rulings, it’s privileged communication. In prison records or domestic violence orders, it’s protective custody. When two readings could fit, the surrounding sentence usually settles it within a line or two.