In the Parassala youth's death case, the police zeroed in on Greeshma based on a suspicion raised by the doctor who performed the victim's post-mortem.
The victim, Sharon Raj had vomited and was taken ill on October 14 after reportedly consuming a spiked Ayurvedic decoction offered by Greeshma. He died in a hospital on October 25.
ADGP MR Ajithkumar said the post-mortem was performed on October 26 and as per the doctor's statement, there was no possibility of Sharon consuming anything acidic.
Earlier, the cops had taken a statement of six persons, including Greeshma, her mother and a cousin. Based on the doctor's suspicion, she was questioned again, on October 27th. "Then we found certain contradictions in her statement," said Ajithkumar.
According to the cops, Greeshma had offered Sharon the Ayurvedic decoction and when he complained of a bitter taste, she gave her fruit juice. Shortly afterward, Sharon felt unwell and began to vomit. He left her house with a friend.
"Sharon's vomit was bluish-green. Usually, such discolouration is seen if the liver and kidney are affected. But the post-mortem did not show traces of any acid consumption. So, we came to the conclusion that this was something else that might have affected the liver and kidney. Then we looked at the possibility of pesticides, including copper sulphate," said Ajithkumar.
By then Greeshma had confessed to having poisoned Sharon and the cops recovered a bottle of Kapiq, a herbicide. This meant it was not copper sulphate that caused the discolouration of the vomit.
"We figured out that one of the components in Kapiq is dye acid blue, which led to our presumption of how the vomit had the discolouration," Ajithkumar said.
Police are expected to arrest Greeshma on Monday.