Gwenonwyn of Aileen by Cher Griffin

Third in the Marla Mesconti Mystery series, this book tells the tale of Gwenonwyn of Aileen, or Layla, as shes called, a rare-colored buckskin Gypsy horse. Layla loses her rider on an organized trail ride when a camouflaged hunter steps out from behind a tree. Layla is nowhere to be found but soon, Marla is called in to help when Layla is found in a pond miles away from the ride. Can Marla and her friends along with Rick Wassel, her police-force boyfriend, find out who did this heinous crime?