Picks the locks for, perhaps

• Aids in illegal activity
• Secures bank blueprints for, maybe
• Watches for, perhaps
• Shelters a fugitive, e.g
• Supports a criminal
• Watches for cops, say
• Looks out for, as a partner in crime
• Aids in criminal activity
• Helps in mischief

Wiktionary Word definitions in Wiktionary
vb. (en-third-person singular of: abet )