accomplice

a person who helps someone else to commit a crime or to do something morally wrong ผู้สมรู้ร่วมคิด

Police said Surasak was a pillion rider on a motorcycle driven by his accomplice Surin Thatthong. 

The next day, on April 30, police received a tipoff that Mr Singkhon had an accomplice, 18-year-old Worachet Thawornpian and they arrested him immediately.

The Criminal Court yesterday approved an arrest warrant for an alleged accomplice of Lebanese national Hussein Atris, questioned in relation to police inquiries about terrorist activity in Bangkok.