Kerala police on Thursday arrested a key suspect in the rape and murder of a 29-year-old Dalit law student in Perumbavoor, Kerala. Reports said the man, a migrant construction worker from Assam, was detained two days ago while he was travelling in the Palakkad-Thissur Highway in Kochi. Four others have also been detained.

Police also claimed the man confessed to committing the crime during interrogation, The News Minute said. Police are questioning him at an undisclosed location, while his blood samples have been sent for DNA testing, the report added. This information has not been independently verified by

Although the police have refused to divulge details, Kerala Chief Minister Pinarayi Vijayan has confirmed that the key suspect has been arrested. According to reports, a black rubber slipper that was found at the crime scene led to this arrest. Earlier, police had released a sketch of whom they believed was the main suspect. The arrest comes more than a month after the murder, which took place on April 28.

Investigators faced criticism after multiple reports said the investigation had been tampered with and not been conducted properly. A report from the National Commission for Women said investigating authorities might not have conducted a fair probe because of “political considerations”. Another independent report said there were “severe lapses” in the police investigation.