There are various situations in which a person can be arrested without warrant. The Code of Criminal Procedure 1973 provides for some of these situations. Under Section 41 of the said Act prescribes for many such situations which are discussed hereunder: i) a person who is concerned in any cognizable offence or against whom a reasonable complaint has been made or credible information has been received or reasonable suspicion exists of his having been so concerned. ii) if a person is found in possession of any implement of house braking without lawful excuse . iii) if a person is proclaimed offender . iv) if a person is found in possession of a property suspected to be stolen and there is reasonable suspicion of his committing the offence v) if a person obstructs a police officers in execution of his duty or has escaped or attempts to escape from lawful custody. vi) if a person is reasonably suspected of being a deserter from any Armed forces of the Union. vii) a person against whom a reasonable complaint has been made or credible information has been received or reasonable suspicion exists of having been concerned in any act committed outside India which would have been a punishable offence in committed in India and for which he is under any law relating to any extradition, or otherwise, liable to be apprehended or detained in custody in India. viii) a person who, being a released convict, commits a breach of any rule made under sub-section (5) of Section 365. xi) a person for whose arrest any requisition, whether written or oral, has been received from another police officer, provided that the requisition specifies the person to be arrested and the offence or other cause for which the arrest is to be made and it appears therefrom that the person might lawfully be arrested without a warrant by the officer who issued the requisition. Under Section 42 0f the said Act any person can be arrested who, in the presence of a police officer, has committed or has been accused of committing a non-cognizable offence refuses, on demand of such officer, to give his name and residence or gives a name or residence which such officer has reason to believe to be false, he may be arrested by such officer in order that his name or residence may be ascertained. But when the true name and residence of such person have been ascertained, he shall be released on his executing a bond, with or without sureties, or appear before a Magistrate is so required. Provided that, if such person is not resident in India, the bond shall be secured by a surety or sureties resident in India. But if the true name and residence of such person could not be ascertained within twenty-four hours from the time of arrest or if he fails to execute the bond, or, if so required, to furnish sufficient sureties, he shall forthwith be forwarded to the nearest Magistrate having jurisdiction. Under Section 43 of the said Act a person can also be arrested by a private person who in his presence commits a non- bailable and cognizable offence, or any proclaimed offender, and, without unnecessary delay, shall make over or cause to be made over any person so arrested to a police officer, or, in the absence of a police officer, take such person or cause him to be taken in custody to the nearest police station. If the police officer has a reason to believe that such person comes under the provisions of Section 41, a police officer shall re-arrest him. If there is reason to believe that he has committed a non-cognizable offence, and he refuses on the demand of a police officer to give his name and residence, or gives a name or residence which such officer has reason to believe to be false, he shall be dealt with under the provisions of Section 42; but if there is no sufficient reason to believe that he has committed any offence, he shall be at once released. Under Section 44 of the said Act when any offence is committed in the presence of a Magistrate, whether Executive or Judicial, within his local jurisdiction, he may himself arrest of order any person to arrest the offender, and may thereupon, subject to the provisions herein contained as to bail, commit the offender to custody. Any Magistrate, whether Executive or Judicial, may order arrest of a person in circumstances to issue a warrant. But in all these cases the person arrested has to be produced before the Magistrate or the officer in charge of the police station without unnecessary delay as per Section 56 of the said Act. Also a person cannot be detained in custody for more than 24 hours without the permission of the Magistrate as per Section 57 of this said Act. Police in all such cases has to report to the District Magistrate or the Sub-Divisional Magistrate about the arrest and also the status of bail as per Section 58 of this said Act. A person can also be arrested without warrant as per certain local laws as applicable from place to place. For example in Delhi as per the Delhi Police Act 1978, a person can be arrested without warrant if an offence u/s 11 of Prevention of Cruelty to Animals Act, 1960, is committed in presence of the Police Officer. Thus it also depends on the area of your residence or on the place where the alleged act in contravention of law is committed and the local law applicable there.