After passing the matriculation examination, he studied at the Notre Dame College in Dhaka and then at the Law Department of the University of Dhaka. He was arrested again during protests against Pakistani ruler Ayub Khan.
He started his career as a lawyer in 1964 after passing his LLB. In 1966 he was enrolled as an advocate of the High Court.
Mehboob was the chief prosecutor of the war crimes court set up after independence, but he was criticized for representing war criminals at the tribunal, set up 40 years after independence.
He had good political connections as a relative of Tofajjal Hussain Manik Miya, the founding editor of Dainik Ittefaq. He actively joined politics in 2008 with BNP.