"Gotta Go," by Elaine Viets, in Alfred Hitchcock's Mystery Magazine, November 2015.
Sorry this review is late. Bouchercon doth make sluggards of us all.
"If you want to be a good-looking corpse, carbon monoxide is the way to go. Your skin is a lovely shade of pink."
That helpful tip is the opening line of this story, which is intended to be the first in a series about Angela Richman, Death Investigator for a Missouri county. In this tale she is looking into the apparent suicide of a wealthy woman, found in her car in a closed garage. The detective in charge of the case is an "errorist," a lazy cop who makes a lot of mistakes. He wants to wrap up this obvious suicide before he goes off-shift. Angela has a couple of hours to find evidence that the death was (surprise!) murder.
The story is full of detail, and has a fair-play ending.