Mistake of person under Section 61 is no defence to the charge, and the ambushers who shot the wrong rider remain guilty of premeditated murder under Section 289(4). ดักซุ่มยิงโดยสำคัญผิดในตัวบุคคล จะยกความสำคัญผิดขึ้นแก้ตัวว่ามิได้กระทำโดยเจตนาฆ่าไม่ได้ตามมาตรา 61 คงมีความผิดฐานฆ่าโดยไตร่ตรองไว้ก่อนตามมาตรา 289(4)

SUPREME COURT DECISION No. 1432/2515
Year: 1972 (B.E. 2515)
Relevant Code Sections: Criminal, Section(s) 61, 289

SUMMARY
The two defendants and their companions lay in wait beside the road for L., expecting him to ride past on his motorcycle. When A. rode past they took him for L. and shot him dead. The point decided is a narrow one, and it is about what the mistake does not do: Section 61 denies a defendant who means to kill one person and by mistake kills another the argument that he therefore acted without intent to kill. The defendants remained guilty of premeditated murder under Section 289(4).

FACTS OF THE CASE
The defendant lay in ambush to kill a specific person but killed the wrong person due to mistaken identity.

COURT'S HOLDING
The Supreme Court held that under Section 61 (mistake of person), mistaken identity is no defense to premeditated murder under Section 289(4).

LEGAL ANALYSIS
Section 61 and Section 60 answer different questions, and this case turns on which of them applies. Section 60 covers the blow that goes astray: the result falls on someone the defendant did not aim at, the law deems the intent to have run to that person, but it expressly withholds any provision that would raise the punishment because of the victim's status or the victim's relationship to the defendant. Section 61 covers the defendant who strikes exactly the person he aimed at and is simply wrong about who that person is, and it carries no such reservation.

That is why the aggravated charge survived here in full. The defendants lay in wait for one man, fired on the rider who came past in the belief that he was that man, and killed him. They aimed at their target and hit it; the error was one of identification. Premeditation under Section 289(4) attaches to the planning the defendants actually did, and the ambush was planned whoever rode into it, so misidentifying the victim took nothing out of the offence.

The consequence is that mistaken identity is not a defence to intent in a Thai homicide case at all. It can only be run as a fact bearing on the separate question of whether the killing was planned in the first place.

PRACTICAL IMPLICATIONS
Aiming at one person and hitting another is not a defence. Section 61 leaves the intent to kill intact where the mistake is only about who the victim was, so a plan that misfires onto a stranger is still premeditated murder under Section 289(4). Evidence that the defendant meant to kill someone else does not reduce the charge, it confirms the premeditation.

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Note: This is an English-language summary of the Thai original judgment.
For the authoritative Thai text, please refer to the Thai version above
or visit deka.supremecourt.or.th.