Are there any records of murders/serial killings among Native American tribes prior to heavy European influence?

There are reports of a small group of systematic Inuit cannibals on Akpatok island in Ungava bay which lured their victims to their island to kill and eat them. They certainly would fit modern definitions of serial killers. The tale came through oral tradition and was dictated to Elijah Johannes by Elijah Angnatuk through Taqralik; I'll post it here in the original tellers prose:

There are many things I cannot remember, but I used to hear stories long ago and now I will tell you one that I can recall. Some parts of it may not be exactly correct, but I will try to present the story as accurately as possible. I heard this story in the old days before the whitemen were even thought of, when our people survived on their own by hunting animals. Inuit seemed more numerous then. There were many mishaps in those days which may have resulted in the decline of the population. Those were eventful times and people were known to kill each other. It may be for this reason that there are not many Inuit today. In those days, no one knew of God's existence. The shamans were the only ones who cared for the sick and received respect from the people. The powerful shamans were not the servants of the devil. They were very intelligent and it seems quite remarkable that they were not aware of God. The Inuit led difficult lives and were sometimes forced to eat miserable things. In fact, some Inuit developed the habit of eating other humans and forgot that animals are the proper source of food. It is said that eating other humans was a joy to some of them. Many people lived on Akpatok Island in those days and others came to visit. The southern shore of the island where boats came to land became known as Nisa-saqvik because people there were known to eat other humans. When animals became scarce and people on Akpatok were threatened with starvation, some people would eat other humans. A few Inuit on the island lived solely on a diet of human flesh. People from Illuili (.the mainland) used to leave their relatives and their original hunting grounds to travel to Akpatok Island and stay for a few months. The area we now inhabit is called Illuili. Long before the days of firearms, only harpoons for sea mammals and spears for birds were used in hunting. In winter time, those who were so inclined devoured other humans as food. Two cannibal brothers by the name of Itigaituk were then living on Akpatok Island. In those days women handled such tasks as fetching water. The two Itigaituks kept a woman captive to do their chores for them and refrained from killing her for food. The brothers would ask their neighbours to visit. They considered the human heart to be good food and when they craved for it they would fool their neighbours by inviting them to feast on human flesh by calling out to them, "Uumanuuna!" But instead of offering food, they were thinking of eating their visitors. The inside of their igloo was shaped like a ditch so that a person entering would slide in through a slippery opening. When the invited person arrived near the entrance of the igloo, he was told to lay down to enter the igloo feet first. The person would do as he was told and slid into the igloo feet first. As the person's body came through the entrance he was stabbed near the heart. And once again the two cannibal brothers had a supply of food. These people were murderers leading despicable lives. Throughout the winter they killed many people who had relatives on the mainland. When the spring thaw arrived, the innards of their human victims lay so thick around their igloo that a person could sink his foot into the mess. There would have been a bigger population of Inuit but they used to kill each other for they knew of neither God nor the devil, even though some were capable of performing shamanism. Perhaps if they hadn't eaten each other and if they had tried to be more prudent, Inuit would now be as numerous as white people. Another thing that limited the population was the periods of starvation when animals were scarce. Storms lasting many days prevented people from going out to hunt and some had to eat each other to survive. Perhaps it is because of these incidents that the Inuit population is so small today. Long ago Inuit and Indians occupied the same territory, but they avoided each other out of fear and because both groups spoke different languages. In fact, the Indians would travel far beyond the tree-line tracking down Inuit at night. That could be another reason why there are not many Inuit. The two Itigaituk brothers are said to have had plenty of food on Akpatok Island. Through an open channel in the ice floes of Ungava Bay they would row their umiaq across to the mainland. When the Itigaituks passed near the camps of people living on Illuili they warned their woman servant not to mention anything about their terrible secret, for she had many relatives living on the mainland. Perhaps the woman was totally against the two brothers and when she had the opportunity to meet Inuit living on Illuili she was thinking of escaping. Finally, the woman could keep the Itigaituks' secret no longer. She told other Inuit what had been happening and her story quickly spread among the people, making everyone aware of the deeds of the Itigaituk brothers on Akpatok. Winter had set in while the two brothers were still on the mainland, which gave the Inuit an opportunity to question the two Itigaituks on their activities. It is said that white people are fearsome, but in those days the Inuit could also be frightening. The Inuit talked about the two brothers and people living in all directions heard the story and decided to do something about the Itigaituks. The Inuit travelled to a gathering place called Initavik near a huge lake which is today called Qalialuk. It is located near Qamanialuk, close by the trail to Qasigiaqsiuvik. The small hill located in that area was covered with the igloos of those who had come to question the two Itigaituks. The Inuit in those days were known to be much tougher with their laws than those who enforce the laws today. One by one the relatives of those who had been eaten interrogated the two brothers about their crimes. Although the two brothers pleaded not guilty, the people decided they were to be executed and sentenced them to a slow and painful death. This story used to be told and therefore I am recounting it now. Long before the governments controlled the people, the Inuit lived a harsh life and faced much famine. They travelled throughout the whole region and survived without the use of firearms. They depended mostly on sea mammals for survival because whales were abundunt and could be harpooned and because the sea provided easier access to animals. Caribou were hunted with bows and arrows and were difficult to locate. Sometimes it seemed as if there were no caribou at all anywhere on this land. That is why most people depended on the sea because it also provided seals. Since the incident of the Itigaituks on Akpatok, not many people have travelled to the island.