Sticks by, as a stickup man

• Helps with a heist, say
• Does lookout duty for, say
• Encourages a scoundrel
• Lends a hand, criminally
• Encourages an evildoer
• Helps plan a job, maybe
• Incites
• Helps, wrongly
• Shelters a fugitive, e.g

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