Police arrested Babu Mondal, the prime suspect in the May 7 Madhyamgram shooting who was often seen in close proximity of transport minister Madan Mitra, late on Thursday.

Mondal was arrested at Sealdah station while he was trying to flee to Ajmer in Rajasthan after being on the run for the past few days, changing cars and even appearance by shaving off his head and trademark moustache.

While the police are yet to gather details, primarily it appears Mondal had plotted the murder of Kamarhati promoter Babu Sen, a business rival, allegedly riding the might of his political patronage.

On May 7, 12-15 men on motorcycles and in a Sumo had waylaid Sen and Nitai Pal, alias Nungkai, on the road that connects Madhyamgram Chowrasta on Jessore Road with Madhyamgram station. They sprayed bullets on the Alto 800 in which Sen and Pal were travelling. While both were killed in the attack, their associate Abhijeet Guha suffered bullet wounds. The driver, Jagadish, escaped unscathed.

"Soon after the murder, Mondal fled to Jharkhand changing cars. From there he reached Purulia and kept moving from one place to another, including Digha and Dankuni," said Bhaskar Mukherjee, the additional police superintendent of North 24-Parganas. "He is one of the prime plotters of the twin murders."

Besides Mondal, the police have arrested six people in connection with the shooting. A manhunt is on for Babu Ghosh, a conspirator who used to work for Mondal, the police said.

Mondal, in his early 40s, took to realty business across parts of Kamarhati, Belghoria and Nimta, on the northern fringe of the city, after Trinamul came to power and Madan Mitra became the MLA of Kamarhati, an erstwhile Left bastion, in 2011.

"With the change of guard, Mondal shifted his allegiance from the CPM's Manas Mukherjee, who lost the 2011 polls from Kamarhati, to Mitra for survival," a senior Trinamul leader said.

"Mondal became the main man behind Mitra's Parisheba, a one-stop shop for serving the needy in Kamarhati. Projecting a different image from that of a promoter, Mondal would sit in the office and handle all requests."

Mondal managed to keep under wraps his growing rivalry with Babu Sen, who too had switched political allegiance and was his neighbour in Deshapriya Nagar in Belghoria.

Babu Sen had a criminal past and was one of the prime accused in the Agarpara twin murders on January 26, 2014.

In his early 50s, Sen was released on bail in January 2015 after a year in custody in connection with the murders.

A police source said Mondal had a conflict of interest with Sen ever since the latter started gaining in strength and made money by filling low-lying areas in Kamarhati, Barasat and along Kalyani Expressway, off Sodepur.

He then decided to enter the business of supplying building materials.

"The rivalry was growing for some time and reached a flashpoint when Sen pooled in money to buy a huge chunk of prime land in Ariadaha, off Kamarhati. Mondal had tried to grab this land parcel, too," said a police officer. "Both the groups fought with each other over this land."

The police on Friday claimed they had enough reasons to believe Mondal, originally from Dhubulia in Nadia, had hatched the plot to kill Sen with the help of Biswajit Saha, alias Bishu, and Pradip Dey, alias Pada, a promoter from Madhyamgram.

As part of the plan, Pada called Sen and Pal for a meeting in Badu, off Madhyamgram, on the fateful afternoon to discuss a land project.

Child sexual abuse

A Barasat court on Friday sentenced a man to 10 years' imprisonment under the Protection of Children from Sexual Offence Act. Sandip Das, 24, used to teach computer at his home in Barasat's Ashwinipally. In 2013, a woman had complained that Sandip had sexually assaulted her eight-year-old daughter and one of her friends during class, police said.

The second additional district judge on Friday sentenced Sandip to 10 and seven years' imprisonment. Both sentences will run concurrently.

Suicide

A first-year BSc student died after jumping off the roof of his college hostel on Friday night.