India, June 30 -- The prime accused arrested in connection with the gangrape of a 24-year-old student at South Calcutta Law College had been planning the assault for several days, police said on Monday.

Three out of the four arrested persons - Monojit Mishra, Pratim Mukherjee and Zaid Ahmed - had pre-planned the crime, PTI quoted a police officer as saying.

The fourth accused in the case was the security guard at the college. Of the three main accused, two are senior students, while Monojit Mishra is a former student of the same institution.

Police also said that the victim had been targeted by the prime accused, Monojit Mishra, from the very first day of her admission to the college.

"The entire matter was premeditated. The trio had ...