The Security Police, or in contracted form, the Espos (or Boys-in-brown in Deal-slang), were the officers of the Corporate Sector Authority's Ground Forces responsible for law enforcement and the defense of the CSA's territories. The name Espo was also a slang term used by smugglers to refer to members of the organization.
Espo troopers making an arrest.
Espos had a reputation for brutality throughout the Corporate Sector. They were distinguished by their brown uniforms and KZZ riot armor. Armed with riot guns, Merr-Sonn stun batons and transparisteel riot shields, they were known to have used brutal and even lethal force against rioters and other sorts of "disobedient" beings and sometimes severe interrogative tactics. They were also widely known for their use of the FC-1 flechette launcher. Espos also had access to heavier weaponry, such as mortars and walkers. Individuals who were convicted of political crimes within the Corporate Sector were sentenced to terms at a secret prison called Stars' End.
Mara Jade hiding from police on Shelkonwa
At some point, the Emperor's Hand Mara Jade was seen hiding behind the wall from two members of the Security Police on the Colonies planet of Shelkonwa.