New Delhi, March 13 -- The Supreme Court has cautioned investigators and courts against building criminal cases on public perception or personal bias, warning that such an approach can derail justice by endangering innocent people while allowing the real perpetrator to escape. A bench of Justices Sanjay Kumar and K Vinod Chandran said that overzealous investigations based on assumptions rather than evidence could be as damaging to the criminal justice process as lethargic or delayed probes. "Overzealous investigation is as fatal to prosecution as are the lethargic and the tardy. Framing a case on public perceptions and personal predilections ends up in a mess, often putting to peril an innocent and always letting free the perpetrator," court said in its judgment on Wednesday. The observation came while the court upheld the acquittal of a man and his wife who had been accused of murdering his parents by setting their house on fire in Bihar in 2016. The court emphasised the human cost of wrongful prosecution, noting that the trauma of arrest, incarceration and trial can permanently scar those who are later found innocent. "The trauma of arrest, incarceration and trial will always scar the couple and more so their children who were left orphaned during the time when their parents were imprisoned," the bench held. Even though the accused were ultimately acquitted, the bench highlighted, the stigma of being accused of killing one's own parents would likely remain. "A couple, at the fag end of their lives, were burnt to death and the cause, whether homicide or accident, eludes civil society," said the court, adding that the shadow of suspicion cast on the family would continue to haunt them. It further underlined: "When lives are lost or taken and there is a possibility of false accusations being made, investigators and courts must strive to do better and follow accepted practices and procedural rules to the hilt." The case concerned the death of an elderly couple whose house was gutted in a fire in the early hours of November 23, 2016. The husband died immediately while his wife succumbed to burn injuries two days later in a Patna hospital. Prosecutors alleged that the younger son and his wife set the hut ablaze due to a longstanding property dispute. A trial court convicted the couple for murder, but the Patna High Court later acquitted them, finding serious gaps in the prosecution's case. The Supreme Court has now affirmed that acquittal, holding that the investigation and prosecution were fundamentally flawed....