Vigneshwaran, V Nagaraj and Gomathi Shankar, arrested on June 16 and lodged in the Central Prison here, were served with the detention orders passed by the Police Commissioner A K Vishwanathan in view of their alleged involvement in similar crimes in the past, a police release said.
They were hatching a plot to eliminate one Manickam, his wife and son when police nabbed them.
On interrogation, it was revealed that Vigneshwaran, the son-in-law of Manickam, was in financial problem and wanted money and planned to eliminate the entire family, so that he can get the property worth crores of rupees.