a party to
abettor
accessary
accessory
accomplice in crime
ally
assistant
associate
coadjutor
coconspirator
cohort
collaborator
colleague
confederate
conspirator
cooperator
copartner
cotenant
fellow
fellow conspirator
henchman
partaker
participant
participator
partner
party
promoter
see
shareholder
sharer
socius criminis
help
helper
supporter
decoy
steerer
adherent
adviser
complicity
comrade
confidant
dupe
follower
informant
instigator
murderer
participation
perpetrator
spy
suspect
traitor
victim
witness