There are many cooks in the criminal justice system kitchen. It’s a good to know who’s who. The following is not a conclusive list, but it explains who many of the players are.
There are several law enforcement agencies. For example, your county sheriff’s department is a separate agency from your local city police department. Most folks simply lump them all together, but it’s good to be aware of the differences. Typically, only one agency will be involved in an arrest. But certainly more than one agency can be involved in some capacity.
Police departments are your local city police officers. The Chief of Police is a city employee who’s appointed, not elected by the public. By contrast, your county Sheriff is an elected public official. He or she runs the Sheriff’s Department. All the officers who work for him or her are called Sheriff’s deputies. As an aside, deputies prefer not to be called “officer”, which implies local police, not county sheriff’s deputies. In either department, when individuals rise within the ranks, for example, to a detective or sergeant, they are called by their new title.
There are other agencies besides police and sheriff’s departments. The California Highway Patrol (“CHP”), for instance, is a state-wide agency. All CHP officers are paid by the State of California, not locally. Their jurisdiction to enforce state laws is not limited to the local county or city.
The vast majority of all criminal cases in state courts stem from arrests made by city police, county sheriff’s deputies, or CHP. But there are other agencies—both local and state—that make arrests. The county Probation Department, for instance, monitors those on probation, which often leads to arrests. Also, your local District Attorney’s Office most likely has its own investigators known as DA Investigators. They, too, have the authority to enforce state laws and make arrests. Generally, DA Investigators are former sheriff’s or police detectives with a lot of experience. They typically will work with prosecutors on unique or complex cases. They also help prosecutors in follow-up investigations, witness interviews, etc. with respect to the DAs’ caseloads in general. Additionally, other state agencies (e.g., Department of Insurance, Department of Fish and Game, etc.) have authority to enforce state laws.
The Federal Bureau of Investigation (“FBI”), as its name suggests, is a federal agency. Their jurisdiction is not limited to California or local matters. Typically, they do not get involved in local cases, including murders (unless it was, for instance, a mafia-related murder).
The District Attorney’s Office - The District Attorney or “DA” is a county elected public official responsible for prosecuting suspected law violators in court. The DA represents the People of the State of California. That’s why in court, the DA will refer to him or herself as “the People” or “the State.” Generally, the DA’s staff of hired attorneys are known as Deputy District Attorneys (“DDAs”). In other states as well as in San Francisco (and possibly other California counties), they are called “Assistant District Attorneys.” But, it's all the same. Also, there are ranks within a DA’s Office one can rise to, such as the Chief Assistant or Chief Deputy DA. No matter where you are or what rank, however, most people simply refer to prosecutors as DAs. IMPORTANTLY, many people don't understand that it’s the DA who decides whether to file criminal charges, no one else. It’s neither the law enforcement agencies nor the alleged victims who decide. For more information, see my section, "THE FILING OF CRIMINAL CHARGES."
The City Attorney’s Office - Some larger cities have, in addition to a DA’s Office, a City Attorney’s Office that handles criminal prosecution. These offices prosecute lower-level non-felony offenses—namely, misdemeanors and municipal violations. The same prosecutorial discretion of DAs applies to Deputy City Attorneys.
The Public Defender’s Office - Public Defenders or “PDs” (not to be confused with the Police Department or prosecutors) are court-appointed attorneys assigned to represent those who cannot afford a private attorney. Per the Sixth Amendment of the US Constitution, the government must provide attorneys to indigent defendants. They are paid by the local county government, just like the local judges, law enforcement, and DA. Typically, each office will have a Chief Public Defender who can either be elected or appointed. Similar to Deputy DAs, the attorneys who work for the Chief Public Defender are Deputy Public Defenders. Not all counties have a Public Defender's Office. For example, San Mateo County has a the Private Defender Program, which is a panel of independent attorneys who take on indigent defense cases. Although in form, San Mateo County's PDP functions similarly to a Public Defender's Office, there are key differences. For example, each client is represented by the individual attorney's practice rather than the office as a whole.
Private Defense Attorneys - All of the other non-government lawyers are simply in private practice and do not have a special name. No matter whether an attorney is a DA, PD, or in private practice, they are all esquires or legal counsel. You will frequently hear judges and lawyers refer generally to other lawyers as simply “counsel”, which can mean one lawyer or a team of lawyers.
Note: Some Other Prosecutors...
The Attorney General’s Office - The head of the United States Department of Justice is known as the Attorney General. Additionally, each state has its own justice department and Attorney General. From a bigger picture point of view of United States government, there are three distinct branches—the executive branch (which includes the President of the United States); the legislative branch (i.e., Congress); and the judicial branch (the courts). The executive branch enforces the laws with the President at the helm. Within that branch is the Attorney General. The California Attorney General Office employs Deputy Attorney Generals (“DAGs”) who, for example, represent the State of California in criminal appeals cases, but occasionally will also prosecute cases in state court. However, they generally only get involved when there’s a particular conflict of interest for the local DA’s Office in its prosecution of a particular individual (for example, the DA’s son).
The United States Attorney’s Office - The United States Attorney’s Office is part of the United Stated Department of Justice. Prosecutors for a U.S. Attorney’s Office are known as Assistant U.S. Attorneys (“AUSAs”). There are offices across the country. In their criminal divisions, they are responsible for prosecuting federal crimes in federal district
courts—often cases stemming from FBI investigations.
The court system in the United States is a bit complex, but briefly it’s divided into a state system and a federal system. Each system has three different levels—the trial court is the first level for either court system. A DUI case, for example, will not be charged in federal court. Rather, it will be charged in your local Superior Court or your local Municipal Court, which is a trial court of limited jurisdiction (e.g., traffic court, small claims, etc.). A federal crime will be prosecuted in a federal district court. The second level or intermediate level of courts in both the state and federal system are the appellate courts (known as "circuit courts" in the federal system), which is where folks go to appeal decisions made in the trial court. Lastly, if you appeal an appellate court decision, your case may be heard at the highest level court — in California, it’s the California Supreme Court; federally, it’s the United States Supreme Court. As a brief note, New York names its courts differently — their trial level courts are called the Supreme Courts and their highest court is called the New York Court of Appeals. Go figure.
Judges - Local judges are elected public officials that serve terms whereas federal judges are appointed by the President with the consent of the Senate for life. What you need to know about trial court judges: In jury trials, the judge essentially acts as the referee — he or she decides on all legal issues, such as which evidence is to be admitted vs excluded and which lawyer objections to sustain (agree with) or overrule (disagree with). By contrast, the jury alone decides the factual issues. A main issue of fact, for example, would be whether the defendant committed the offense. A lot of people believe their fate rests in the hands in the judge. But, unless you chose to have a “court trial”, which is a trial by judge only and no jury, then that’s simply not the case. It’s really the jury that holds the power to convict or acquit you. However, if convicted, the judge, not the jury, will decide your punishment. There are specific sentencing guidelines to follow, so you should know the range of “exposure” (your potential jail or prison time) you face before trial.
“Plaintiff” vs “Defendant” - The plaintiff is the party who’s responsible for bringing forward the case. In civil cases, the plaintiff is the party that filed the lawsuit. In criminal cases, the plaintiff, generally, is the DA who filed criminal charges. The defendant, is the party that is forced to answer to either the lawsuit or criminal charges.
Here’s a fun fact: In a courtroom, the plaintiff’s table is always closest to the jury box. In other words, the criminal defendant sits farther away from the jury. I believe this practice developed from concerns about juror safety and to minimize the potential effect of juror intimidation by criminal defendants sitting nearby.
OTHER PEOPLE IN COURT
In addition to the judge, every courtroom will have a bailiff, court clerk, and court reporter. The bailiff is generally a sheriff’s deputy assigned to keep order in the courtroom and protect the judge. The court clerk is in charge of all administrative duties. Lastly, the court reporter is the unsung hero of the court who writes down all that is said in court verbatim, which is incredibly impressive and amazes me daily.