New Delhi, April 22: The “insanity” plea that Praveen Mahajan’s lawyer hinted at soon after he shot older brother Pramod might prove to be a tough line to take in court.

An accused is exonerated only if he is able to prove that at the time of commission of the crime he was incapable of knowing the nature of the act or that what he was doing was wrong or contrary to law.

But with Praveen himself walking up to the police station to surrender, legal experts say his lawyer would find it difficult to establish that his client was of “unsound” mind.

According to a 1972 Supreme Court judgment, the conduct of an accused just before the offence, at the time of committing the crime and immediately after is most relevant while deciding whether the person was of unsound mind.

“The fact that the accused committed the murder over a trifling matter and made a clean breast of his crime would not go to show that he was insane,” the court clarified in another judgment two years later.

In another case where the accused did not try to run away after pushing a four-year-old child into a fire, Orissa High Court had absolved him of all charges.

The courts have made it clear that medical insanity is different from legal insanity. While medical insanity takes into account how much a person is conscious of the effect of his act on others, legal insanity is decided on the basis of his consciousness in relation to himself.

Explaining legal insanity, a famous commentary on criminal law says a person who cuts off the head of a sleeping man because “it would be great fun to see him looking for it when he woke up” would be covered by the exception carved out in penal code.