This guy had a much longer record than any known white serial killer. Impressive, given the way he had so many run-ins with the law. Whereas Ted Bundy had a list of victims half as numerous. Of course, Bundy targeted average co-eds, whereas Little sought out women on the margins - typically druggies, prostitutes, etc. An interesting profile of this guy:
https://www.thecut.com/2018/12/how-serial-killer-samuel-little-was-caught.html
There are always a few predators in society, but I think there was a period in time from the late 60s through the early 1990s where it was possible for these kind of serial killers to go undetected for long periods.
Prior to the late 60s, tighter community bonds and social conventions allowed people to ask questions. Police officers, hotel clerks, gas station attendants, and servers at the local diner would all ask: “where are you from?”, “what’s your business here in town?”, “how long are you staying for?”. Part of this was friendliness, but part was also to be on the lookout for trouble. And they would ask those questions both of potential troublemakers and potential victims.
After the mid-60s, a lot of traditional social structures broke down and it became considered invasive, rude and possibly discrimantory to inquire too much about other people’s business. This made it easy for predators to travel about the country and blend in unnoticed, and for their victims to go mostly unnoticed as they disappeared.
From the 1990s onward, technology has made it much more difficult to remain anonymous. DNA testing has become so sophisticated that it’s highly unlikely that killer leaves no evidence. Credit card receipts, GPS, toll booth, and video cameras make it almost impossible to travel without creating a record.
I think these types of killers still exist, but they are now usually caught after far fewer victims.