Law and Order ADGP M R Ajith Kumar on Sunday confirmed that 22-year-old Literature post graduate student Greeshma had indeed plotted the murder of Sharon, a 23-year-old radiology student who was once her lover.

At this stage, the involvement of other members of Greeshma's family, her parents or her uncle, is not clear. “From what we have collected till now, there is no evidence of the involvement of others,” the ADGP told reporters late on Sunday. There is also no prima facie evidence to suggest that similar attempts were made on Sharon's life before this.

ADGP Ajith Kumar was meeting the press after an eight-hour grilling of the prime accused, Greeshma. The ADGP said that Greeshma had called Sharon to her house with the sole intention of killing him and erasing him from her life forever.

Greeshma herself had made the poison that Sharon consumed. She is said to have made him drink the ayurveda concoction, surreptitiously mixed with poison, as part of a dare. It is said that Sharon used to tease her for constantly cribbing about consuming the bitter medicine. She then asked him to consume it and see for himself. “At first, he did not drink the concoction in full. It was at the second attempt that Sharon could manage to gulp down what Greeshma gave him. After this, Greeshma also gave him a mango drink to mask the bitterness,” the ADGP said.

The poison was not copper sulphate as was earlier surmised. It was a herbicide named Kapiq. It has an ingredient called 'acid dye blue', which the ADGP said would have caused the greenish-blue discolouration of Sharon right after he had consumed the ayurveda medicine mixed with Kapiq.

It was a forensic doctor's suspicion that led the police to look at the pesticide angle. The doctor had suggested that the greenish-blue vomit could be the result of consuming copper sulphate, a common pesticide. “The forensic doctor had also said that there are no signs of acid intake. This goaded us to think of the other possibilities of discoloration. We found that this could happen only when the liver or the kidneys are affected. But we could not confirm the copper sulphate theory,” he said.

It was Greeshma herself, after the interrogators broke her defence, who revealed that Kapiq was used. This herbicide did not have copper sulphate. The Kapiq bottle, which Greeshma had thrown away, has also been retrieved by the police.

During the interrogation, Greeshma claimed that she had resorted to poisoning Sharon as a last resort. “She seemed to suggest that she had attempted soft methods earlier to somehow make him break this relationship,” the ADGP said.

He said the story of the astrologer's prediction that her first husband would die was something that she cooked up to scare him into leaving her. The ADGP also undermined the marriage theory. “They were not married. It is true that they had gone to a church and he had applied 'kumkum' on her forehead. But there was no marriage,” he said.

Greeshma also did not tell her interrogators of Sharon having ever blackmailed her using private pictures. He said that Sharon, in his death statement given on October 21, had not expressed anything suspicious about Greeshma.

However, the ADGP hinted that Sharon's life could have been saved had Greeshma told Sharon's brother of the poison that she had used. “His brother had called her while Sharon was still in hospital. He repeatedly asked her what she had given him. Perhaps out of fear, she insisted that it was only an ayurveda medicine. Had she told him, Shron perhaps could have been saved,” Ajith Kumar said.

From what he understood from the questioning, the ADGP said that the Sharon-Greeshma affair was a love-hate one. “Their relationship soured after her marriage was fixed. But a month-and-a-half later, they got back. According to her, she somehow wanted him out of her life,” the ADGP said. He said that Sharon used to pressure her a lot, but did not elaborate how.

The ADGP also said that there was no delay on the part of the police. “The police were alerted only when an intimation of Sharon's death on October 25 was sent out by the Medical College. In fact, in the death statement given by Sharon to the police on October 21, he did not say anything that would incriminate Greeshma. However, once the police were informed of Sharon's death, Greeshma and her relatives and also Sharon's friends and relatives were questioned on October 26 and 27. It was the contradictions found in some of the statements that we used to break Greeshma down during the interrogation,” the ADGP said.

Greeshma's arrest would soon be recorded. The ADGP said that all that Greeshma said during the interrogation would be cross verified in the coming days to arrive at a clearer and conclusive picture of the crime.