East Princeton White Collar Crime Lawyer, Massachusetts

An exception to the general rule that a police officer needs an arrest warrant before he can enter a home to make an arrest. If a felony has just occurred and an officer has chased a suspect to a private house, the officer can forcefully enter the house in order to prevent the suspect from escaping or hiding or destroying evidence.

An affirmative defense to a crime. Self-defense is the use of reasonable force to protect oneself from an aggressor. Self-defense shields a person from criminal liability for the harm inflicted on the aggressor. For example, a robbery victim who takes the robber's weapon and uses it against the robber during a struggle won't be liable for assault and battery since he can show that his action was reasonably necessary to protect himself from imminent harm.

A decision by a judge or jury that a defendant in a criminal case is not guilty of a crime. An acquittal is not a finding of innocence; it is simply a conclusion that the prosecution has not proved its case beyond a reasonable doubt.

A lawyer who is elected to represent a state government in criminal cases in a designated county or judicial district. A D.A.'s duties typically include reviewing police arrest reports, deciding whether to bring criminal charges against arrested people and prosecuting criminal cases in court. The D.A. may also supervise other attorneys, called Deputy District Attorneys or Assistant District Attorneys. In some states a District Attorney may be called a Prosecuting Attorney, County Attorney or State's Attorney. In the federal system, the equivalent to the D.A. is a United States Attorney. The country has many U.S. Attorneys, each appointed by the President, who supervise regional offices staffed with prosecutors called Assistant United States Attorneys.

A formal investigation -- governed by court rules -- that is conducted before trial. Discovery allows one party to question other parties, and sometimes witnesses. It also allows one party to force the others to produce requested documents or other physical evidence. The most common types of discovery are interrogatories, consisting of written questions the other party must answer under penalty of perjury, and depositions, which involve an in-person session at which one party to a lawsuit has the opportunity to ask oral questions of the other party or her witnesses under oath while a written transcript is made by a court reporter. Other types of pretrial discovery consist of written requests to produce documents and requests for admissions, by which one party asks the other to admit or deny key facts in the case. One major purpose of discovery is to assess the strength or weakness of an opponent's case, with the idea of opening settlement talks. Another is to gather information to use at trial. Discovery is also present in criminal cases, in which by law the prosecutor must turn over to the defense any witness statements and any evidence that might tend to exonerate the defendant. Depending on the rules of the court, the defendant may also be obliged to share evidence with the prosecutor.

The amount and quality of information police must have before they can arrest or search without a warrant or that a judge must have before she will sign a search warrant allowing the police to conduct a search or arrest a suspect. Reliable information must show that it's more likely than not that a crime has occurred and the suspect is involved.

An agreement to do something or to allow something to happen, made with complete knowledge of all relevant facts, such as the risks involved or any available alternatives. For example, a patient may give informed consent to medical treatment only after the healthcare professional has disclosed all possible risks involved in accepting or rejecting the treatment. A healthcare provider or facility may be held responsible for an injury caused by an undisclosed risk. In another context, a person accused of committing a crime cannot give up his constitutional rights--for example, to remain silent or to talk with an attorney--unless and until he has been informed of those rights, usually via the well-known Miranda warnings.

The crime of operating a motor vehicle while under the influence of alcohol or drugs, including prescription drugs. Complete intoxication is not required; the level of alcohol or drugs in the driver's body must simply be enough to prevent him from thinking clearly or driving safely. State laws specify the levels of blood alcohol content at which a person is presumed to be under the influence. Also called driving while intoxicated (DWI and drunk driving).

Evidence that proves a fact by means of an inference. For example, from the evidence that a person was seen running away from the scene of a crime, a judge or jury may infer that the person committed the crime.