The Bihar government has made changes in the police brass and appointed an officer who had played a crucial role in the conviction of Siwan don Mohammad Shahabuddin as the next additional director-general, headquarters, considered a key position in the hierarchy.

According to a notification issued by the home department on Saturday, 1988 batch IPS officer S.K. Singhal will take over as ADG (headquarters) from Sunil Kumar, who was promoted to the rank of director-general in January.

Singhal was posted as ADG in the Bihar Military Police (BMP) before being elevated to the coveted post.

The post of ADG headquarters is crucial in the police structure as the person manning it is considered to be the virtual second-in-command after the DGP.

Singhal was among 14 IPS officers transferred by the government on Saturday.

Four police ranges - Patna, Bhagalpur, Tirhut and Darbhanga - have also got new deputy inspectors-general (DIGs).

Singhal was in the limelight in 1996 when he was attacked by don-turned-politician Shahabuddin in Siwan where he was posted as the superintendent of police. In 2007, a special court sentenced Shahabuddin to 10 years' imprisonment in connection with the attack on Singhal.

Outgoing ADG (headquarters) Sunil Kumar, a 1987 batch IPS officer, has been made director-general, Bihar Police Academy (BPA), which is yet to be made operational. Kumar, considered to be a favourite of former chief minister Lalu Prasad, has also been given additional charge of director-general, BMP.

The appointment of Singhal as ADG (headquarters) assumes significance as Shahabuddin was recently shifted to Delhi's Tihar Jail from Siwan on the state government's initiative. Singhal, who had lodged a written complaint in 1996 with Darauli police station in Siwan against Shahabuddin, who was then the RJD MLA from Zeradei, showed interest in the trial and deposed before the court on time, which finally led to conviction of the Siwan strongman.

Sources in the police headquarters said that by appointing Singhal as ADG (headquarters), the government has sent a strong message to the officials given field assignments, especially those posted as superintendents of police in the districts. Before his return from central deputation, Singhal had served with the Sashastra Seema Bal in Bihar as its IG.

Rajesh Kumar, a 2003 batch IPS officer, will be the next DIG, Patna central range. His batchmate Vikas Vaibhav, a former SSP of Patna, will join as DIG, Bhagalpur range. Khagaria SP Anil Kumar Singh has been promoted as DIG, Tirhut range.

Upendra Kumar Sinha (1999 batch) has been posted as IG, vigilance investigation bureau; Binod will be the next DIG, Darbhanga. Ratna Mani Sanjeev will be the new commandant of BMP-5 stationed in Patna. Babu Ram, who was removed as Aurangabad SP when 10 Cobra jawans were killed by Maoists last year and was waiting for posting, has been named commandant, BMP-7, Katihar.