Locals said the youth had set fire to her father’s shop at Perinthalamanna to divert the attention before targeting the young woman.
Double Olympic medallist Sushil Kumar has been on the run since May 4 after his name was linked to the murder of a former wrestler.
A preliminary investigation into the deaths of a young woman and her two babies suggested that her husband might have injected them with poison.
Sanu Mohan had planned a suicide pact with his family, but refrained from suggesting it to his wife fearing her opposition.
The car was brought to Thrikkakara from Coimbatore, and the detailed forensic examination was carried out on Friday.
Investigators also confiscated his car and Vaiga’s gold ornaments, which he had sold in Coimbatore to fund his life in hiding.
Achyuthan was arrested after police tracked him using his mobile phone location, which revealed that he had not left Vallikkunnam.
Sanu Mohan’s mother, Sarala, said that she had no contacts with her son for five years. When his father Mohanan died four years ago, the family had no means of contacting him, Sarala said.
Based on the information given by the accused, the body was found at the plot that was 350 metres from Subeera's house.
The murdered youth was Shaji Peter, aka 'Karadi' Shaji, of Bharathipuram near Anchal in Kollam. Shaji's mother Ponnamma, 68; and his brother Sajin Peter, 30; are in the custody of the Eroor police.