This Little Piggy. Kappy King Mystery Kapers, #4

They only came to buy a pig. Jimmy Peachey, lover of all animals, has finally done it. He's finally convinced his sister, Edie, to allow him to raise pigs. But when he, Edie, and Kappy arrive at the farm to buy the swine, they have another surprise in store. Balthazar Lapp, the ultra-conservative Amish pig farmer, is lying on the floor of his greenhouse, bludgeoned to death. After an anonymous caller tips off police, Jimmy's friend Tiny is arrested for the murder.
Jimmy begs Edie and Kappy to help get his friend out of jail, but with a prison record and the possible murder weapon found in his car, Tiny will remain behind bars.  Yet strange things are still happening around the valley. Corn is mysteriously growing at the abandoned farm behind Edie and Jimmy's house. Balthazar's wife disappears just days after his death along with all his livestock and the huge crop of medicinal marijuana from his greenhouse.
And Jimmy is convinced that the Lapps' neighbor, Gerald Kent, stole one of their pigs-the very same, 'special' pig Balthazar had been trying to sell to Tiny on the day of his murder. It'll take all Kappy's wits to put the clues together and figure out who the murderer is, but it's only at the Third Annual Smoking in the Valley barbecue competition that she uncovers just how special this little piggy really is.