Justice M Jaichandran and Justice S Nagamuthu of the Madurai Bench of the high court also ordered Rs 5 lakh compensation to the next of kin of the victims.
The lower court had sentenced Katturaja and Vettumperumal to death (on four counts) for murdering four of a family -- a man, his wife and two minor girls -- on April 19, 2007.
The Additional District and Sessions judge had sentenced them to two life terms under the Scheduled Castes and Tribes (Prevention of Atrocities) Act and causing death with weapons and slapped a fine of Rs 2.25 lakh on the accused.
"If there is slackness on the part of the stakeholders, the end result will be failure of justice. In this case, we confess that it is a failure of justice and the criminals who committed the act did not get punished," the bench said.
More From This Section
The judges said they had given a chance to police to further investigate the case as they were not satisfied with the probe and evidence was not legally acceptable. But Additional Superintendent of Police P Manoharan heading the team had not rectified the flaws pointed out. There were a lot of infirmities in investigation and no improvement in probe.
Normally the sub-inspector's evidence is not rejected in the court. But here the SI had neither identified the murder weapon nor taken steps to do DNA tests. The bicycle of the deceased was not produced as evidence as also a crowbar used to break into the house of the victims.
Holding the investigation should have been done carefully given that four lives were lost, the bench said, "Our belief in police is shattered. We don't have sufficient evidence to hold that the accused are perpetrators of the crime."
The bench recalled that government had assured it during hearing another case on June 6 this year that the victim compensation scheme would be implemented in 45 days. But the Public prosecutor had now stated it was under preparation.
The prosecution case was Katturja had murdered the family as he was angry with Jayakumar over his alleged illicit relationship with his wife.
Katturaja confessed to the murder and the other person surrendered later.