The Principal Sessions Court on August 22 had observed that the murder of Kevin P Joseph, involving his wife's relatives, was a case of honour killing.
All the 10 accused who were found guilty under various sections of the Indian Penal Code, including 302 (murder), 364A (kidnapping for ransom) and Section 506 (2) (Punishment for criminal intimidation) have been awarded double life term in the case, Special Public Prosecutor C S Ajayan told reporters in Kottayam.
Three people including prime accused Syaanu Chacko, Kevin's brother-in-law, were also convicted under IPC Section 120 (b) (Criminal conspiracy).
There were 14 accused in the case.
Four people including Kevin's father-in-law Chacko were acquitted for want of evidence.
The death of Kevin, who was abducted along with a relative from Mannanam in the district, had sparked protests in the state.
The victim's kin had alleged that he died due to police laxity as they refused to conduct an investigation on the basis of his wife's complaint.
Kevin's body was found on May 28 last year in a stream in Chaliyakkara in Kollam district.
The couple had married at a registrar's office in Ettumanoor against the wishes of her family.
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