以上術(shù)語均有策劃、鼓勵、協(xié)助或唆使他人犯重罪，即具有“從犯”（accessory)的含義。按傳統(tǒng)，“從犯”曾包括accessory before the fact (事前從犯）和 accessory after the fact (事后從犯）兩類。accessory before the fact 和 principal (主犯）的區(qū)別在于前者未出現(xiàn)而后者則出現(xiàn)在犯罪現(xiàn)場，目前美國多數(shù)州的法規(guī)已經(jīng)廢除此種區(qū)分而將accessory before the fact當作共犯歸類為principal [1]。accessory after the fact則是指明知有人犯重罪而協(xié)助、庇護該罪犯以逃避司法懲處之從犯，現(xiàn)多數(shù)州已不再籠統(tǒng)使用此術(shù)語，而將其分為若干具體的犯罪，如干擾司法罪“obstructing  justice” 等。
 
[1 ] “The traditional distinction between accessories before the fact and principals, that accessories were not present and principals were present at the commission of the crime, is not recognized under most modem state statutes. Accessories before the fact are usually considered principals. ” Cf. Linda Picard Wood, J. D.，Merriam Webster's Dictionary of Law, at p. 6, Meniam-Webster, Incorporated, Springfield, Massachusetts (1996).
[2 ] “ Many state statutes now omit the term accessory after the fact and instead characterized the accessory as having committed a particular offense, such as obstructing justice. ”Id. at p. 6.