State Advocate General Kishor Datta has approached the division bench of Justice Debangshu Basak and Justice Shabbar Rashidi seeking a "death penalty" for the convict.

The division bench has admitted the petition from the state government.

After the court pronounced the quantum of sentence, Chief Minister Mamata Banerjee announced on Monday evening that the state government would approach the Calcutta High Court challenging the verdict.

She also said the state government will be seeking the "death penalty" for the convict.

"I strongly feel that it is a heinous crime that warrants capital punishment. We will plead for capital punishment of the convict at the High Court now," the Chief Minister said in a statement.

According to her, she was deeply shocked at the judgment of the special court which did not consider the crime as the "rarest of rare".

"I am convinced that it is indeed a rarest of rare cases which demands capital punishment. We want to insist upon the death penalty in this most sinister and sensitive case," the Chief Minister said in a statement.

"Recently, in the last 3/4 months, we have been able to ensure capital/ maximum punishment for convicts in such crimes. Then, why, in this case, has capital punishment not been awarded?" the Chief Minister’s statement added.

"We demanded the 'death penalty' for the convict. I don't know how….Had the case been in our hands (read state police or Kolkata Police), the death sentence would have been pronounced much earlier," the Chief Minister said.

While pronouncing the quantum of sentence, special court judge Anirban Das said that the Central Bureau of Investigation (CBI)'s contention that Roy's offence in the matter was "the rarest and rare crimes" was not tenable.