Preface: I don't think there is a single-word (verb) that expresses the concept I am asking for, in which case I'd settle for the least ambiguous and most common phrase or idiom that describes the following situation.
I was reading a short story from a private student of mine when I came across this line:
Lucy realized she had the proof to frame Robert [for the murders].
To frame someone is to arrange or plant evidence in such a way that an innocent person appears to be guilty in the eyes of the law. My student's sentence would be fine if Robert were innocent of the crime, or if there was no evidence that linked Robert to the murders but somehow Lucy managed to plant false evidence which resulted in his arrest.
But in my student's story, Robert isn't innocent. He did commit the two murders and the evidence Lucy found was not planted, nor false, but led to the police arresting him for the two murders.
I suggested the following solutions:
Lucy realized she found the proof that nailed Robert for the murders
Lucy realized she found the proof to incriminate Robert.
Lucy realized she found the evidence which proved Robert's guilt.
Lucy found the smoking gun that proved Robert's guilt.
Sentences 1 and 2 are fine within the plot of the story but taken out of context, they could still suggest Robert was set up by Lucy, i.e. he was innocent. Sentences 3 and 4 are, I think, the least ambiguous. My student liked the expression “smoking gun” but added:
A smoking gun is not a verb, I still have to say Lucy found the smoking gun which incriminated Robert.
If “to frame” someone is to plant evidence that ‘proves’ an innocent person is guilty, is there a verb that means: to find evidence that unequivocally proves a person is guilty? Perhaps there is an obscure legal term hidden in OED, or maybe an obsolete expression, which escapes me. Here is my student's sentence with the blank space.
Lucy realized she had the proof to _________ Robert
But I am open to other suggestions and solutions so long as its clear that the evidence shows us that Robert is guilty.
Am I right to ascertain sentences 1 and 2 are possibly ambiguous? And finally, are there other alternatives to the ones I suggested?