This article examines the militia – the Soviet regular police force – and its criminal investigation branch in the context of the state's dramatic expansion during the Russian civil war, 1917–21. It argues that, although the Bolsheviks harboured ideological doubts about centralized police forces, they quickly came to regard the militia as a key fulcrum of the revolutionary state, evidenced not least by the re-establishment of a unitary force under central state supervision, by its rapid growth during the civil war, and by efforts to ensure its political reliability. Despite the importance attached to the militia, however, it remained a dysfunctional organization during the 1917–21 period. Its criminal investigation branch, in particular, was afflicted by a range of operational problems that undermined its ability to function as an effective arm of the state. This suggests a counter-narrative to the assumption that statization in itself conferred extensive coercive influence upon the Bolshevik regime. Despite the dramatic growth of the state during the civil war, its traction at the grassroots of society remained uneven and unpredictable.