Praveen Mahajan outside the Mumbai court on Tuesday. (AP)

New Delhi, Dec. 18: Yesterday, Praveen Mahajan waved. Today, he could not stop smiling.

Between the wave and the smile, Praveen had been found guilty of murdering his blood brother and sentenced to life in prison.

What was he so proud about that he kept grinning? He did escape death but being condemned to prison at the age of 48 is no laughing matter.

Psychiatrists said the unmistakable signs of nonchalance could reflect a sense of achievement and satisfaction, not uncommon among sibling murderers.

Psychoanalysis could help clarify how a person facing possible death — the life sentence was given in the afternoon — could appear so relaxed in the morning. But psychiatrists familiar with criminal minds said the response could stem from a conviction of having done no wrong.

“I’ve seen this earlier on the faces of people who’ve given a meaning to their acts. There’s a sense of satisfaction, a feeling that they’ve done the right thing,” said Rajat Mitra, a psychiatrist who’s worked with inmates at Delhi’s Tihar Jail.

Even after the murder of a sibling, a person convinced that what he had done was correct could be genuinely happy, said Sandeep Vohra, a consultant psychiatrist at the Apollo Indraprastha Hospital, New Delhi.

Mitra said when siblings have detached themselves from each other, the act of murder “could be as easy as killing a stranger”. Such detachment could emerge from either humiliation or a deep sense of contempt for a sibling, he said.

“The source of the humiliation could be genuine, or something entirely imagined. Unfairness in the treatment by parents or by the sibling, or perceived injustice,” Mitra said. “The murder then serves as a way to get back lost status.”

But the psychiatrists also cautioned that in the absence of psychiatric evaluation, they were unable to rule out the possibility that Praveen’s indifferent reactions to his conviction might stem from a desire to appear to be in control.

Doctors cite instances where politicians who’ve been brought to court or convicted are sometimes seen greeting or waving to the gathered crowds.

Anand Mohan, a former MP from Bihar, had waved at his supporters while he was being led away from court after being sentenced to death for the murder of a district magistrate.

“When you’re in the limelight, there could be a tendency to project a bold front and maintain a facade of someone who’s cool — even though at the back of the mind, there are concerns about the implications of what’s happening,” Vohra said.