Mistake Of Law And Mistake Of Facts: A Defence

There are two purposes that are served by the criminal justice system. The primary goal is to impose corrective measures in order to prevent criminal acts from occurring. Its secondary goal is to repair the mental state of the person or people accountable for the illegal act.

If it was only the former which was the goal of criminal law, it would be used to punish the conduct itself, regardless of the fact that it had been done unintentionally, negligently, or intentionally.

The law, on the other hand, appears to intend to penalise those who are the ones who are responsible for the conduct, and responsibility appears to suggest a particular mental state—in this case, a guilty mind.

In criminal law, the maxim “actus non facit reum nisi mensit rea” has taken on a powerful presence. The idea of making a mistake as an excuse has come to be accepted as a result of this maxim.

The general idea is that a person is to be judged responsible for his actions if he knows and intends the natural consequences of his actions. There are, however, several exceptions to this general norm, in which a person may be absolved of his crime.

One such justification is the lack of mens rea. The mistaken identity defence is founded on the premise that a person who is mistaken or unaware of the existence of a fact cannot create the necessary intent to commit a crime and hence is not legally accountable for his actions.

The common law principle “ignorantia facit doth excusat, ignorantia juris non excusat” (ignorance of fact excuses, ignorance of the law does not excuse) has been incorporated into this.

The seventeenth-century case of R. v. Levett, in which an accused was acquitted on this basis, demonstrates the principle’s extensive application. Following this, there has been significant progress in the law relating to mistakes, despite the fact that there is still confusion about the actual scope of this defence.

Furthermore, the jurisprudence and regulations governing this defence continue to differ from nation to country, necessitating a comparison of the positions in different countries. The main concerns surrounding the use of error as a defence are whether or not there are any extra conditions or qualifications. 

What is Mistake under IPC?

When there arises any discrepancy between objectively existing facts and subjective impressions of those facts by any individual, the issue of mistake arises. Traditionally, mistakes have been divided into factual and legal errors, i.e., errors which result from a misunderstanding of facts as they exist against errors which result from an error in the prevailing legal position. 

Mens rea is a Latin term that loosely translates to “guilty mind.” It can take several forms, which include intent, knowledge, negligence, and so forth. Any offence, unless it is a strict liability offence, there lies a requirement of the presence of a mental element. The mens rea of the crime is formed by this mental component.

Evidence of a real factual error, which would make the offender’s act innocent if the facts existed as the offender thought them to, would, in principle, negate the mens rea and result in the acquittal.

Since it is required that a person must intend to create all of the consequences that he has in fact produced if he has to be held criminally accountable for the consequences, a mistake of fact that eliminates an intention to cause a result banned by law is a defence. In the case of a legal error, it is argued that the current stance of not permitting it as a defence has to be reconsidered. 

In terms of the fact that he did not want to break the law, the same concept applies in the event of a factual error, i.e., the person did not intend for the consequences to occur. As a result, it is proposed that at least a reasonable legal error be permitted as a defence.

In common law, the law in this regard was established by the decision of Director of Public Prosecutions v. Morgan, which stated that where the offence requires either intent or recklessness as part of its ingredients, a mistake of fact that precludes both states of mind will excuse, regardless of whether the mistake is reasonable or not. 


Since it prevents the accused from generating the requisite mens rea, ignorance of the facts is an excuse. It refutes the concept of mens rea.

For example: – When moving towards the church the man after checking, left the gun unloaded. During his absence, though, someone else went out shooting with the gun and left it loaded while keeping it back.

Later on that particular day, when the owner picked up the gun again and he accidentally touched the trigger which in turn killed her wife. The man had good reason to assume that the weapon was unloaded. Therefore, he cannot be said to be guilty.

The error must be such that it is of one of the important facts, which means that, the facts that are necessary to the offence purportedly committed by the accused. He must be completely unaware of the facts of the case, which in turn would make his actions illegal. When the accused is unaware of the true facts, his actions should not be interpreted as that the accused did it with an intention.

However, in certain situations where the accused’s act is wrong in itself but is not criminal, his ignorance of the real circumstances which make the act unlawful is no defence. A similar was stated by the court in the case of King Emperor v Tustipada Mandal .

For example: – When A strikes B, for example, B is knocked out. A, believing B is dead, sets fire to the body and burns it; A’s behaviour is not innocent, even if he is acting on the basis of a genuine error of fact. In the case of King Emperor v Sree Narayan the court was of the opinion that it cannot be said to be a factual error for the purpose of avoiding criminal culpability because he had burned B’s body to erase the evidence of his previous act of striking B and the resultant consequences.

Even in such situations when the act is not authorised by law, it is not an offence if it has been done in the good faith if it is justified by law, according to section 79 of the IPC. As a result, when an accused mistakenly mistook a human being in the bush for a wild animal at night and killed the deceased, the accused was found not guilty. When an accused killed a person with the false idea that the person who entered his residence with the intent to kill him did so with the intent to kill him, the accused’s actions were judged to be justified in law, and they were so acquitted of liability. 

Ignorantia facti excusat, on the other hand, is subject to two provisos being satisfied. First, a factual error cannot be effectively argued when a thorough investigation would have revealed the genuine facts. Secondly, when an actus reus is offered without reference to the doer’s mens rea, it cannot be recognised as a plea.


The notion “ignorance of the law is no excuse,” which states that a wrongdoer cannot use ignorance of the law as a shield to evade criminal culpability, is based on the premise that everyone is supposed, if not required, to know the law. As a result, ignorance of those facts that one is required to know does not absolve him from the liability. It is nothing more than a legal fiction which is devised for the purpose of convenience and need. As a result, even if made in good faith, a legal error, fair or unreasonable, it cannot serve as an absolving factor. It may, however, in certain cases, it might act as a mitigating element. 

This assumption is plainly based on a misunderstanding of the real-world situation. In truth, even lawyers who are supposed to be knowing all the laws cannot be familiar with all of the provisions of law due to the vast number of statutory legislations present. 

In the case of King Emperor v Tustipada Mandal had said that as understood in India, a mistake of law encompasses both a mistake as to whether or not there is any law on a given issue and a mistake as to what the law is. The legal fiction of ignoranceia juris non excusat, on the other hand, is justified in the public interest. It is stated that if ignorance of the law is accepted as an absolving factor, then every accused will most probably raise the defence of mistake of law, which would make it difficult for the prosecution to contradict it and establish affirmatively that the accused knew the law which was in question. In the absence of the evidence, the judges would be forced to decide whether the accused was truly unaware of the law. It would also create innumerable complexities, making the administration of justice practically impossible and adding an element of uncertainty to the process. If the mistakes of law are allowed, then it would most probably lead to the encouragement of the ignorance of the law. 


It is the mistake of fact which is the defence available to the accused. This has been clarified in the code itself and the various judgements as well. In the case of Chirangi v. the State of M.P, the court while deciding the liability of the accused stated that it was the mistake of the fact that the accused had been immunized from his liability. 

The distinction which exists between mistakes of fact and mistakes of law is essentially based on their ability to serve as defences; as a result, there are attempts by the accused to portray that a mistake is one regarding the fact rather than being one of law.

As a result, the position that is advised is as follows. In the Indian context, every factual error must meet the criteria of good faith in order to serve as an excuse. Legal errors, on the other hand, should only be accepted as a defence if they are acceptable. It is proposed that the above arrangement would best serve the goals of justice.  It has been presumed under the law that all the people are well aware of the penal laws in the country except for a few categories of the people like minors or lunatics.  


(ed.), D. K. (2018). P.S.A. Pillai’s Criminal Law. Nagpur: LexisNexis ButterworthsWadhwa.

Hallevy, G. (2021). Ignoring the Law in the Name of Honor. SCC Online, 28-62.

Kamath, A. M. (2021). Why Doesn’t Ignorantia Juris Excuse?-A Study of the Law Relating to Mistakes. SCC Online , 10-20.

Shephard, H. (2021). MISTAKE OF FACT. SCC Online, 46-47.


Similar Interesting Reads>>

One thought on “Mistake Of Law And Mistake Of Facts: A Defence

Leave a Reply

2nd National Moot Court Competition, 2023 || Register Now!