Green’s Dictionary of Slang

sancocho v.

[Sp. ‘to cut up into little pieces and stew’]

(drugs) to steal.

[US](con. 1982–6) T. Williams Cocaine Kids (1990) 108: To sancocho is to steal crack, drugs or money from a friend or other person who is not alert, a regular practice in the crack house.
[US]T. Williams Crackhouse 79: Some want to have sex, others want to sancocho, others want to go out on missions.
[US]ONDCP Street Terms 18: Sancocho (Spanish) — To steal.