The Vows of Silence by Susan Hill

A madman is killing young women around the town of Lafferton. He is mainly targeting recently married or engaged females. DCS Simon Serrailler and his team always seem to be one step behind the murderer, since he isn't leaving behind many clues. On a personal front, Serrailler is as isolated from everyone as ever, except his triplet sister Cat Deerbon. Cat, a doctor who is married with three children, has recently returned from a sabbatical in Australia. When a crisis strikes her family, she needs Simon more than ever. In addition, chaplain Jane Fitzroy is thinking about Simon and what might have been between them (Jane was introduced in Hill's last Serrailler mystery, The Risk of Darkness). Will Jane and Simon come out of their individual seclusions? I did enjoy this fourth book in the series (even though the storyline of Cat's crisis was excessive). However, I don't think it's quite up to the same level as the other books in the series, which were outstanding. The Vows of Silence hasn't been published yet in the U.S.