An alibi (/ˈæləbaɪ/, from the Latin, alibī, meaning "somewhere else") is a statement by a person under suspicion in a crime that they were in a different place when the offence was committed.
During a police investigation, all suspects are usually asked to provide details of their whereabouts during the relevant time period, which, where possible, would usually be confirmed by other persons or in other ways (such as by checking phone records, or credit card receipts, use of CCTV, etc.).
[2] Conversely, some judges in other jurisdictions have held the opinion that the mandatory early disclosure of alibis is unfair, possibly even unconstitutional.
[3] The giving of a false alibi, beside resulting in possible subsequent criminal offences (obstruction of justice, perjury, etc.
In Canada, the giving of a false alibi may be used by the court as actual evidence of guilt, provided certain requirements are met.