"Investigation is on and the arrested lady is being treated at a hospital in Katihar where her condition is stated to be out of danger. She was grilled by the DIG (Purnia) and other senior police officials," a top police officer said.
DGP Neelmani has directed Purnia SP N H Khan to ensure that the charge sheet in the case is filed by tomorrow for speedy trial, the official said.
There was no evidence to suggest that Rupam Pathak had ever blackmailed the slain legislator while levelling sexual harassment charges against him, he said.
"Of course what prompted her to take the extreme step is also part of our investigation," the official said.
Additional Director General of Police (Headquarters) P K Thakur said the murder appeared to be premeditated and not perpetrated in a fit of pique that the police did not look into her complaint.
He said the woman had retracted her statement of sexual harassment against Keshari before a judicial magistrate and her husband too had recorded his statement in support of the MLA.
"The case is being probed from all angles," he said.
The 51-year-old four-time BJP MLA was yesterday stabbed to death here by Pathak who had earlier accused him of sexual harassment. Pathak had to be hospitalised after being thrashed by other visitors, present at the MLA`s residence, after the incident.
Chief Minister Nitish Kumar directed the DGP to constitute a high-level probe team, review the security of all legislators and ensure that those who visited them were frisked.