Police arrested the registrar of National Institute of Mental Health & Hospital (NIMH) from city's Sher-e-Bangla Nagar area on Tuesday over the death of senior assistant superintendent of police Anisul Karim, reports UNB.
The arrestee is Abdullah Al Mamun, the hospital's registrar.
Police arrested Abdullah from near the hospital around noon after being tipped-off, said deputy commissioner Harun ur Rashid of Tejgaon crime division of the DMP.
So far, 13 people have been arrested in connection with ASP Anisul's death.
Anisul had been suffering from mental illness and was brought to Mind Aid for treatment on 9 November.
The accused forcefully took the victim to the observation room of the hospital and beat him repeatedly, CCTV footage showed.
Also, the hospital staff informed Anisul's family that he had fainted. And when the police officer's relatives took him to the National Institute of Cardiovascular Diseases, he was declared dead.
Later, Anisul's father filed a case at Adabor police station against 15 people on the following day.