Chapters 20-21 and Conclusion Summary

Wilson takes the knife and compares the prints to all those of every woman he has ever fingerprinted. Wilson believes the killer is the woman he saw in Tom's bedroom some months before. However, none of the fingerprints match. Wilson is frustrated, afraid that Luigi and Angelo might be convicted of murder because he cannot prove another person was in the house. However, while looking through his glass slides one night during the trial, Wilson gets a break. Tom stops by the house to visit and picks up the glass slide on which Roxana once put her prints. When Wilson takes the slide back, he sees Tom's fingerprints and recognizes them at once as those on the knife. Wilson puts it all together, realizing that Tom was the woman he saw, dressed in female clothing, and that...