Ten special teams set up by the district police interrogated several villagers over the last fortnight and finally zeroed in on three suspects on Tuesday.
Three sisters - aged 6, 9 and 11 - went missing from their school on February 14 and their bodies were found on February inside in a well near a farmhouse, about 1 km from the village.
The preliminary post mortem had confirmed that they were raped and murdered. However, forensic findings contradicted the report. The swabs from the girls' vaginas and other body parts were sent to the forensic lab of the government-run medical college at Nagpur. The samples showed no trace of semen. The findings were also inconclusive as to whether the girls were murdered.
The panicky district police sought a second opinion from the experts of forensic department of government medical college on the issue. In response, the department sought more evidence to arrive at a conclusion.