By Steve Gorman and Daniel Trotta LOS ANGELES (Reuters) -Five men have been arrested on suspicion of murdering six people last week in a remote patch of California’s Mojave Desert, a mass killing investigators believe stemmed from the illicit marijuana trade, local law enforcement officials said on Monday. The six victims, all men, were shot to death, and four of them also were partially burned, their bodies left strewn in a grisly crime scene discovered last Tuesday night at the junction of two dirt roads about 60 miles (97 km) northeast of Los Angeles, officials said. Authorities said the vi…