We come to a little difficulty here, since Mrs. Inglethorp never drank it."
( We ( ( ( ( ( ( come ( to ( a ( little difficulty ) ) ) ) here ) , ) ( since ( ( Mrs. Inglethorp ) ( never ( drank it ) ) ) ) ) . ) '' ) )
(ROOT (S (NP (PRP We)) (VP (VBP come) (PP (TO to) (NP (DT a) (JJ little) (NN difficulty))) (ADVP (RB here)) (, ,) (SBAR (IN since) (S (NP (NNP Mrs.) (NNP Inglethorp)) (ADVP (RB never)) (VP (VBD drank) (NP (PRP it)))))) (. .) ('' '')))
Therefore, Mrs. Inglethorp is not the murderer. 
( Therefore ( , ( ( Mrs. Inglethorp ) ( ( ( is not ) ( the murderer ) ) . ) ) ) )
(ROOT (S (ADVP (RB Therefore)) (, ,) (NP (NNP Mrs.) (NNP Inglethorp)) (VP (VBZ is) (RB not) (NP (DT the) (NN murderer))) (. .)))