His American Detective (Victorian Gay Detective #1)
Summer Devon

Lawton, now called Edmund Sloan, is a wealthy young gentleman and philanthropist. He’s spent most of his life pushing all memories of his old family and that horrific day from his thoughts. Now a brash, provocative American detective insists he dredge up the past.
Together, Patrick and the unwilling Edmund must uncover the truth of the murders before the killer strikes again, whether it is in New York or London. As they hunt down secrets from his past, Edmund can’t hide his other secret from the sharp-eyed detective: the attraction he feels for men and the enticing Patrick in particular.