(delivering oral judgment): The respondent in this appeal was charged in the Magistrate's Court at Kuala Lumpur for being in possession of eight plastic straws containing 0.21 gms of heroin, an offence under section 12(2) of the Dangerous Drugs Act No. 30 of 1952 (Revised 1980). Under section 12(3) of the Act, the offence is punishable with a fine not exceeding $20,000 or to imprisonment for a term not exceeding five years or to both. The respondent pleaded guilty to the charge on November 26, 1980 and he was accordingly convicted and sentenced to eight months' imprisonment to take effect from the date of his arrest which was November 8, 1980. The Public Prosecutor has now appealed against sentence. The learned Deputy Public Prosecutor argues that the sentence is grossly inadequate on the ground that the Magistrate had failed to appreciate the seriousness of the offence and also had failed to consider that the respondent had five previous convictions — two of which were connected with drugs whilst the other three involved thefts.

From the grounds of judgment, the learned Magistrate had this to say on sentence:

"Considering the accused's previous conviction and especially 2 previous offences relating to opium and the amount of heroin he is charged with now — it was in my opinion fair and adequate to sentence him to 8 months' imprisonment with effect from date of arrest. It is especially because of the quantity which is 0.21 gms which made me give him an 8 months' imprisonment term instead of a longer one."

It seems clear from the grounds of judgment that although in assessing sentence the learned Magistrate did consider the respondent's previous convictions, she took into account the small quantity of heroin involved as a principal mitigating factor. Section 173(m)(2) of the Criminal Procedure Code provides:

"If the court finds the accused guilty or if a plea of guilty has been recorded and accepted the court shall pass sentence according to law."

A "sentence according to law" means that the sentence must not only be within the ambit of the punishable section, but it must also be assessed and passed in accordance with established judicial principles. In assessing sentence, one of the main factors to be considered is whether the convicted person is a first offender. It is for this purpose that before passing sentence, a Magistrate is required to call for evidence or information regarding the background, antecedent and character of the accused. Where the convicted person has previous records and admits them as correct, the court must consider whether the offence or offences committed previously were of similar nature as the one with which he is presently charged. The court must then consider the sentences imposed in the previous convictions for similar offences to determine whether they have had any deterrent effect on him. Where he is found to be a persistent offender for a similar type of offences, then it is in the interest of justice that a deterrent sentence should be passed and, in such a case, unless there are exceptional circumstances, the quantity, nature or value of the subject-matter of the offence with which he is currently charged can very rarely constitute a mitigating factor.

In the present case, the learned Magistrate failed to take into account that in the two previous convictions for opium offences, the respondent had been sentenced to one year imprisonment in April 1977 and six months' imprisonment in October 1979. The present drug offence was committed in November 1980. Coupled with the other three previous convictions involving thefts for which various terms of imprisonment were passed, the Magistrate should not have found the quantity of 0.21 gms of heroin — the subject-matter in the present charge — as a mitigating factor in the absence of other exceptional circumstances. On the contrary, this fact should have been taken against him on the ground that despite the sentence of imprisonment on t