RV Murders - Jim Richards Murder Mysteries, #40

Here's the synopsis: Jim and Penny have retired from chasing criminals around Las Vegas and decide to go on a cross country vacation in their motorhome. Their first stop is in Lake Havasu to visit the London Bridge. While in the campground there turns up a strange case of murder. A man in an RV across from Jim and Penny finds himself in bed with a strange dead woman, who is not his wife and who is now missing.
The police find too many twists in the case and the lead detective allows Jim and Penny to tag along while he tracks down the killer. So far it looks like a drug cartel murder or a bad case of prostitution gone wrong. Will Jim and Penny help catch the killer and avoid being murder by a drug lord.