Section 78 — Warrantless arrest by officers
Statutory text (Thai original)
พนักงานฝ่ายปกครองหรือตำรวจจะจับผู้ใดโดยไม่มีหมายจับหรือคำสั่งของศาลนั้นไม่ได้
เว้นแต่
(๑) เมื่อบุคคลนั้นได้กระทำความผิดซึ่งหน้าดังได้บัญญัติไว้ในมาตรา
๘๐
(๒)
เมื่อพบบุคคลโดยมีพฤติการณ์อันควรสงสัยว่าผู้นั้นน่าจะก่อเหตุร้ายให้เกิดภยันตรายแก่บุคคลหรือทรัพย์สินของผู้อื่นโดยมีเครื่องมือ
อาวุธ หรือวัตถุอย่างอื่นอันสามารถอาจใช้ในการกระทำความผิด
(๓) เมื่อมีเหตุที่จะออกหมายจับบุคคลนั้นตามมาตรา
๖๖
(๒) แต่มีความจำเป็นเร่งด่วนที่ไม่อาจขอให้ศาลออกหมายจับบุคคลนั้นได้
(๔)
เป็นการจับผู้ต้องหาหรือจำเลยที่หนีหรือจะหลบหนีในระหว่างถูกปล่อยชั่วคราวตามมาตรา
๑๑๗
English translation
An administrative or police officer may not arrest any person without an arrest warrant or a court order, except: (1) when that person has committed a flagrant offense as provided in Section 80; (2) when a person is found under circumstances giving reasonable suspicion that they are about to cause harm to the person or property of another, and are carrying tools, weapons, or other objects capable of being used to commit an offense; (3) when there is a ground to issue an arrest warrant against that person under Section 66(2), but there is an urgent necessity such that an arrest warrant cannot be applied for from the court; (4) where it is the arrest of an alleged offender or defendant who has fled or is about to flee while under provisional release pursuant to Section 117.
This English translation is provided for reference only and has not yet been firm-verified — always rely on the Thai original.
Firm annotation
Section 78 states the core rule that officers may not arrest without an arrest warrant or court order, then lists the four exhaustive exceptions. The exceptions cover a flagrant offense under Section 80, a person found in suspicious circumstances carrying items capable of causing harm, a case falling under the arrest-warrant ground in Section 66(2) where urgency prevents applying to the court, and the arrest of a person who has fled or is fleeing while on provisional release under Section 117. Because warrantless arrest is the exception, courts examine each ground strictly: the urgency exception in (3) requires both a Section 66(2) ground and genuine urgent necessity, and a warrantless arrest is only justified where one of these exceptions truly applies. Detention under special statutes, such as military powers, is treated as something other than an arrest under this section.
Why this matters in practice
This is the section that decides whether a warrantless arrest was lawful, which matters both for people who are arrested and for officers who may face liability. If officers arrest without a warrant, the arrest must fit squarely within one of the four exceptions; a mere hunch is not enough, and the urgency exception in particular needs both a proper ground and real urgency. Note that being caught with contraband, such as drugs, is typically a flagrant offense allowing arrest without a warrant. If you were arrested without a warrant and think none of the exceptions applied, that is a point to raise with a lawyer; you can arrange an online consultation with a Thai lawyer.
Supreme Court decisions interpreting this section
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Supreme Court Judgment No. 3803/2562 (2019)
A warrantless arrest under Section 78(3) requires both a ground under Section 66(2) and a genuine urgent necessity that prevents applying for a warrant; absent these, the arrest and detention are unlawful.
Officers arrested the four plaintiffs without a warrant and held them at the police station until the next afternoon. Examining whether this was an offense in office and against liberty, the Court quoted Section 78(3) and Section 66, underscoring that a warrantless arrest on the urgency ground requires both a Section 66(2) ground and an urgent necessity preventing a warrant application.
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Supreme Court Judgment No. 4316/2560 (2017)
Where officers find a person in possession of drugs, that is a flagrant offense, and they may arrest without a warrant under Section 78(1) read with Section 80.
On searching, officers found methamphetamine on one defendant and a larger quantity in a room the other admitted was his, a flagrant offense. The Court held that the officers had authority to arrest both without an arrest warrant under Section 78(1) and Section 80, so the search and arrest were lawful.
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Supreme Court Judgment No. 10072/2559 (2016)
Detention of a person by military officers under a special statute empowering them to hold a person for questioning is not an arrest under Section 78.
Military officers had held the defendant under a statute allowing detention for questioning for up to seven days before he fled. The Court held that this was detention under the special military power, not an arrest under Section 78, even though police officers were present, and it distinguished the Section 78 rule that officers may not arrest without a warrant except in the listed cases.
Curated decisions with case numbers verified against the Supreme Court database. English renderings are the firm's editorial translation for study.
Frequently asked questions
When can police arrest without a warrant in Thailand?
Under Section 78, only in four cases: a flagrant offense under Section 80, a person carrying a weapon or tool in suspicious circumstances, an urgent case with a Section 66(2) ground where no warrant can be obtained in time, or a person fleeing while on provisional release under Section 117.
Is a warrantless arrest for drug possession lawful?
Yes. Being found in possession of drugs is generally a flagrant offense, so officers may arrest without a warrant under Section 78(1) read with Section 80.
What does the urgent-necessity exception in Section 78(3) require?
It requires both a ground to issue an arrest warrant under Section 66(2) and a genuine urgent necessity meaning a warrant cannot be applied for in time. Without both, a warrantless arrest on this ground is unlawful.