Plot flaw in 'Brotherly Love'?? ** SPOILERS **

** SPOILERS **
** SPOILERS **

In 'Brotherly Love', I don't see how Maggie Harvey could have killed the second prostitute (Joyce Watkins).

Two reasons:

1. We are told that Joyce's body had traces of semen, from unprotected sex shortly before her death, whose DNA matched that found on the first victim (Jean McIlvanney), who was definitely killed by Maggie's husband David.

2. At the time Joyce is killed, Maggie and brother-in-law Michael are being interviewed by Fitz at the police station, while David Harvey is already in custody. The screenplay switches between the interview scene, and those of Joyce's battered body tumbling down the stairs outside her apartment.

Since all three potential suspects (David, Maggie, Father Michael) have alibis, Joyce must have been killed by a fourth person. But then how do we explain the matching DNA??

Furthermore, given all of this evidence, that both Fitz and the police ultimately attribute the killing to Maggie makes no sense to me. In 'Lemming', we know that the police (more correctly, DCI Bilborough) are more concerned about 'results' than justice, while Fitz protests vehemently about Cassidy's innocence. But here Fitz is apparently happy to allow Maggie to take the rap for all three murders. I know that Maggie confesses to all three, but that also includes Jean (which Fitz correctly reasons is to keep her husband out of prison, so that their children will be left at least one parent). Presumably Fitz is motivated more here by compassion than justice??

Or am I missing something?

Thanks to anybody who can clarify.

David

** SPOILERS **
** SPOILERS **