Arrest

CP § 2-203. Warrantless arrests -- Commission of specified crimes

(a) In general. -- A police officer without a warrant may arrest a person if the police officer has probable cause to believe:
(1) that the person has committed a crime listed in subsection (b) of this section; and
(2) that unless the person is arrested immediately, the person:
(i) may not be apprehended;
(ii) may cause physical injury or property damage to another; or
(iii) may tamper with, dispose of, or destroy evidence.
(b) Specified crimes. -- The crimes referred to in subsection (a)(1) of this section are:
(1) manslaughter by vehicle or vessel under § 2-209 of the Criminal Law Article;
(2) malicious burning under § 6-104 or § 6-105 of the Criminal Law Article or an attempt to commit the crime;
(3) malicious mischief under § 6-301 of the Criminal Law Article or an attempt to commit the crime;
(4) a theft crime where the value of the property or services stolen is less than $ 1,000 under § 7-104 or § 7-105 of the Criminal Law Article or an attempt to commit the crime;
(5) the crime of giving or causing to be given a false alarm of fire under § 9-604 of the Criminal Law Article;
(6) indecent exposure under § 11-107 of the Criminal Law Article;
(7) a crime that relates to controlled dangerous substances under Title 5 of the Criminal Law Article or an attempt to commit the crime;
(8) the wearing, carrying, or transporting of a handgun under § 4-203 or § 4-204 of the Criminal Law Article;
(9) carrying or wearing a concealed weapon under § 4-101 of the Criminal Law Article;
(10) prostitution and related crimes under Title 11, Subtitle 3 of the Criminal Law Article; and
(11) violation of a condition of pretrial or posttrial release under § 5-213.1 of this article.

CP § 2-204. Warrantless arrests -- For domestic abuse
(a) In general. -- A police officer without a warrant may arrest a person if:
(1) the police officer has probable cause to believe that:
(i) the person battered the person's spouse or another person with whom the person resides;
(ii) there is evidence of physical injury; and
(iii) unless the person is arrested immediately, the person:
1. may not be apprehended;
2. may cause physical injury or property damage to another; or
3. may tamper with, dispose of, or destroy evidence; and
(2) a report to the police was made within 48 hours of the alleged incident.
(b) Self-defense. --
If the police officer has probable cause to believe that mutual battery occurred and arrest is necessary under subsection (a) of this section, the police officer shall consider whether one of the persons acted in self-defense when determining whether to arrest the person whom the police officer believes to be the primary aggressor.

CP § 2-204.1. Warrantless arrests --For violation of protective order
A police officer shall arrest with or without a warrant and take into custody a person who the officer has probable cause to believe is in violation of a protective order as described in § 4-508.1(c) or § 4-509(b) of the Family Law Article.

CP § 2-205. Warrantless arrests -- For stalking
A police officer without a warrant may arrest a person if:
(1) the police officer has probable cause to believe the person has engaged in stalking under § 3-802 of the Criminal Law Article;
(2) there is credible evidence other than the statements of the alleged stalking victim to support the probable cause under item (1) of this section; and
(3) the police officer has reason to believe that the alleged stalking victim or another person is in danger of imminent bodily harm or death.

CP § 2-206. Warrantless arrests during state of emergency
(a) Scope of section. -- This section applies during a public emergency, as defined in § 14-301(c)(1) or (2) of the Public Safety Article, and when public safety is imperiled, or on reasonable apprehension of immediate danger of public safety being imperiled.
(b) In general. -- During a time described in subsection (a) of this section, the authority to make an arrest without a warrant granted to police officers under this title is granted to a person who:
(1) is serving under a proclamation of a state of emergency issued by the Governor, as provided in § 14-303 of the Public Safety Article, as:
(i) a member of a law enforcement unit that is listed in § 2-101(c) of this title; or
(ii) a member of the militia called into action by the Governor, as provided in § 14-306 of the Public Safety Article;
(2) is serving as a member of the militia ordered into active service by the Governor under § 13-702 of the Public Safety Article; or
(3) is a member of the armed forces of the United States under orders to aid civil authorities of the State in enforcing law and order, subject to subsection (c) of this section.
(c) Effect of section. -- The grant of authority under subsection (b)(3) of this section does not limit or impair any power or duty of a member of the armed forces of the United States or authorize any action incompatible with federal law or regulations.

We have defined an arrest in general terms as the detention of a known or suspected offender for the purpose of prosecuting him for a crime.
Longshore v. State, 399 Md. 486, 502 (2007)

An arrest is the taking, seizing, or detaining of the person of another (1) by touching or putting hands on him; (2) or by any act that indicates an intention to take him into custody and that subjects him to the actual control and will of the person making the arrest; or (3) by the consent of the person to be arrested. 5 Am.Jur.2d Arrest § 1 (1962). It is said that four elements must ordinarily coalesce to constitute a legal arrest: (1) an intent to arrest; (2) under real or pretended authority; (3) accompanied by a seizure or detention of the person; and (4) which is understood by the person arrested.
State v. Evans, 352 Md. 496, 513 (Md. 1999)

whether the officer intends that a detention lead to a prosecution has no bearing on whether an arrest has occurred.
State v. Evans, 352 Md. 496, 514 (Md. 1999) (where Defendant claimed that p/o didn’t arrest them and therefore couldn’t search where they were released to be prosecuted later)

for a lawful arrest in Maryland for the commission of a felony, a police officer must have probable cause to believe the suspect has committed a felony and must either physically restrain the suspect or otherwise subject the suspect to his or her custody and control.
State v. Evans, 352 Md. 496, 515 (Md. 1999)

Cotton's reliance on the facts that he was handcuffed, placed under guard, and given Miranda warnings as establishing that he was de facto arrested either upon his initial detention or after fifteen to twenty minutes of it finds no substantial support in either Federal or this Court's current jurisprudence.
Cotton v. State, 386 Md. 249, 267 (Md. 2005)

the standard of probable cause "applies to all arrests, without the need to 'balance' the interests and circumstances involved in particular situations." Dunaway v. New York, 442 U.S. 200, 208, 60 L. Ed. 2d 824, 99 S. Ct. 2248 (1979). If an officer has probable cause to believe that an individual has committed even a very minor criminal offense in his presence, he may, without violating the Fourth Amendment, arrest the offender.
Atwater v. City of Lago Vista, 532 U.S. 318, 354 (2001) (seat belt arrest ok)