Arrest of a person might be necessary under the following circumstances –
1) As a preventive or precautionary measure : If there is imminent danger of the commission of a serious crime (cognizable offence), arrest of the person intending to commit such crime may become necessary as a preventive measure (Section 151Cr.P.C.). There may be other circumstances where it is necessary as a precautionary measure to arrest a habitual offender or an ex-convict (Section 41(2) read with Section 110) or a person found under suspicious circumstances (Section 41(1)(b) &(d), Section 41(2) read with Section 109).
2) For securing attendance of accused at trial : When a person is to be tried on the charge of some crime, his attendance at the time of trial becomes necessary. If his attendance is not likely to be ensured by issuing a notice or summons to him, probably his arrest and detention is the only effective method of securing his presence at the trial. (Section 87, 204).
3) For obtaining correct name and address : Where a person, on being asked by a police officer, refuses to give his name and address, then under certain circumstances, it would be proper on the part of the police to arrest such a person with a view to ascertain his correct name and address (Section 42).
4) For removing obstruction to police : Whoever obstructs a police officer in the execution of his duty is liable to be arrested then and there by such a police officer. This is essential for effective discharge of police duties. (Section 41(1)(e)) 5) For retaking a person escaped from custody :
A person who has escaped from lawful custody is liable to be arrested forthwith by the police. (Section 41(1)(e)) The decision to arrest should be made fairly having regard to the liberty of the individual and the interests of the society. Ideally, a judicial officer is best suited to decide such issues with a fair measure of reasonableness, impartiality and detachment.
Therefore, basically it is for a magistrate to make an arrest-decision on the information generally obtained from the police or the complainant. If the magistrate makes a decision to arrest, he would issue a warrant of arrest.
An arrest warrant is a written order signed, sealed and issued by a magistrate and addressed to a police officer or some other person specially named and commanding him to arrest the body of the accused person named in it.