Most predators target the most vulnerable, easiest prey. They do not want a fight - they don't want to risk harm to themselves. So elders that have a particular vulnerability are attractive to them. That vulnerability might be dementia or something similar, but like Rosie52 said - they might just be lonely and wanting a connection. Male elders often get taken advantage of by younger women, even when there is no sexual relationship. Female elders often get taken by young women with a child, especially a baby. Good point, Rosie66!