It's important to note that this was not a planned act of murder. Voldemort, as a young boy named Tom Riddle, was attempting to understand his magical abilities and the nature of his parentage. In the process, he accidentally killed his father with a burst of magic. This event, combined with his later murder of his mother and the Muggle caretaker, solidified his belief in his own superiority and fueled his desire for immortality, leading him to create horcruxes.