"A Murder of Brides," by Sulari Gentill, in The Perfect Crime, edited by Maxim Jakubowski, Harper Collins, 2022.
We're in Australia in the 1920s. Gus and Harriet make a precarious living as traveling photographers. They specialize in brides and grooms, but since they only hit a town every few months they are taking pictures of recent newlyweds, not the actual nuptials. They "advertise a pledge to deliver a wedding portrait while the couple was still in love."
Today a policeman asks them to photograph the scene of a brutal murder. Fortunately for the cops they have a ready-made suspect, and he's even a Chinese servant. Who will quarrel with such a simple solution? Only the photographers see a flaw...
The special treat in this story is the guest who is traveling around with our heroes. He's a writer and you might say he has a bit of an obsession. His identity is not exactly a secret, but I won't spoil it for you.