You'll need a character with the Handcuffs ability in their stats. Albion/police officers have that ability. although I noticed that it's not shown as their abilities but when you switch to them and use the character wheel it's there. so maybe all of them have that. recruit an Albion Contractor(found in the Tower of London in the City of London district. zoom enough and you'll see areas that glow red, hover on them to see their name) switch to them and press
rotate around and toggle on the handcuff ability. then simply press
to arrest civilians or enemies 5 times.