Meet R.K Singh, the former district magistrate of Samastipur in 1990. It is said that he was tasked with arresting L K Advani as he brought his rath yatra to Bihar, on the way to Ayodhya in Uttar Pradesh from Somnath in Gujarat. Lalu Prasad Yadav was the chief minister then. However, BJP seemed to be unfazed by the arrest and it was the same L K Advani picked him to work as joint secretary in the Home Ministry from 1999 to 2004 when the NDA was in power.

He later served as the Union home secretary under the Congress party-led United Progressive alliance from 30th June 2011 to 30th June 2013. Although he was appreciated  for his work in the Congress circuit, Singh joined the BJP amid much fanfare, expressing his admiration for the party's approach on issues of national security.

He was, however, again in news because he criticised the then home minister Sushil Kumar Shinde, his former boss after joining the BJP. During his tenure at the defence ministry, he also flagged the Tatra-BEML deal. In fact, he had objected to the way the deal was struck where  Tatra Sipox, UK had used a questionable means to indigenise Tatra vehicles even though BEML had a transfer of technology pact with the supplying firm. When Nitish Kumar formed the government in Bihar, this 1975-batch IAS officer was made the principal secretary of road construction department and played an important role in improving the road network in the state.

He was also appointed the principal secretary of the disaster management department where he became instrumental in relief and rescue operation during the 2008 Kosi floods.