Section 35 of the 1999 constitution gurantees bail as a basic conditional right. A person may be denied of his personal liberty, for the purpose of bringing him before a court in execution of the court order, upon reasonable suspicion of his having committed a criminal offence or to prevent his committing the offence.
Bail arises of three stages of criminal justice process;
[a] The police may release a suspect on bail pending further investigation.
[b] The court may release an accused person on bail pending the determination of the case against him.
[c] The court may release a convicted person on bail pending the determination of his appeal against his conviction.
So either the police or the court may grant bail. Section 27 of the police Act states that “When a person is arrested without a warrant, he shall be taken before a magistrate who has jurisdiction with respect to the offence with which he is charged or is empowered to deal with him under section 484 of the criminal procedure Act as soon as practicable, after he is taken into custody; provided that any police officer for the time being in charge of the police station may inquire into the case and:-
[a] except when the case appears to such officer to be of a serious nature, may release such person upon his entering into a recognisance with or without sureties for a reasonable amount, to appear before a magistrate at the day, time and place mentioned in the recognisance: or
[b] if it appears to such officer that such inquiry cannot be completed forthwith, may release such person on his entering into a recognisance, with or without sureties for a reasonable amount, to appear at such police station and at such time as are named in the recognisance, unless he previously receives notice in writing from the superior police officer in charge of that police station, that his attendance is not required, and any such bond may be enforced as if it were a recognisance conditional for the appearance of the said person before a magistrate.
Also section 17 of the criminal procedure Act provides that;
“When any person has been taken into custody without a warrant for an offence other than an offence punishable with death, any officer in charge of the police station may in any case, and shall, if it will not be practicable to bring such person before a magistrate or justice of peace having jurisdiction with respect to the offence charged within twenty- four hours after he was so taken into custody, inquire into the case, and , unless the offence appears to such officer to be of a serious nature, discharge the person upon his entering into a recognisance with or without sureties for reasonable amount to appear before a court at the time and place named in the recognisance but where such person is retained in custody he shall be brought before a court or justice of peace having jurisdiction with respect to the offence or empowered to deal with such person by section 484 of this Act as soon as practicable whether the police inquiries are completed.”
In the case of Eda V. commissioner of police  3 NCLR 219 the phrase “as soon as practicable” was held to be inconsistent with the specific periods provided for by section 35  and  of the 1999 constitution. The phrase is therefore null and void to the extent that it is inconsistent with the specific provisions of sections 35  and 
Section 18 of the criminal procedure Act provides that when a person is arrested without warrant of arrest pursuant to section 17 of the C.P.A, for an offence other than that punishable with death, if it appears to the officer in charge of the station that inquiry into the case cannot be completed forthwith, he may discharge the said person on bail. The bail shall be upon his entering into a recognsance, with or without sureties, for a reasonable amount to appear at the police station at such time as the police may require his attendance, unless he receives notice in writing from the officer in charge of the station that his attendance is not required. Such recognisance is enforceable as if it were a recognisance conditional for the appearance of the person before a magistrate court in the same district as the police station.
However, the following conditions must be considered for the grant or refusal of bail:-
1. When there is an evidence before the court that the accused person is likely to or has already included in acts which might interfere with further investigation of the case or the conduct of the proceedings at his trial, his application for bail may not be granted as was the case in Bamaiyi V. The state  3.S.C 53 at 76. Where inducement was intended to facilitate the retrieval of incriminating evidence against him, in custody of the police.
2. The gravity of the offence also influences the courts discretion to grant or withhold bail, even though an accused is presume-med innocent until proven guilty and therefore ordinarily is entitled to bail
3. Where there is likelihood of the accused person committing another offence if released on bail, the court will withhold bail. In R.V.Jammal.  16 N.L.R. 54, the accused person committed an offence while he was on bail for an earlier charge. His application for bail on the later offence was rejected.
4. An accused person’s criminal record is to be taken into consideration in the grant or refusal of bail, A first offender is more likely to be admitted to bail than a habitual criminal. The fact that a person has not been convicted for crime is a prima facie evidence of good character, until the contrary is proved. Such a person will readily be granted bail pending his trail.
5. A person charged with an offence may not be admitted to bail if the offence alleged is prevalent in the areas where the accused resides. Note that bail is not just intended to secure the attendance of an accused person for his trial, it is also necessary to discourage the commission of offences that have attained high frequency of occurrence, such as obtaining by false pretence.
6. The ill health of an accused person is a relevant factor in the grant of his application for bail, but note also that there must be proof before the court that the accused person is not only ill but that it will be judicious to grant him bail. In Fawehinmi V State  N. W.L.R [pt 127] 486, the court of Appeal considers the ill health of the accused person sufficient special circumstance to grant him bail.
It is worthy to note that an application for bail should not be refused as a punitive measure.