The documents say Kight admitted to driving the boat when it hit people swimming near an anchored boat.
In the documents, the investigator said Kight had a strong odor of alcohol on his breath, had red, glassy eyes, and his speech was hard to understand.
Kight also admitted that no one was looking forward on the boat, and that people were wakeboarding behind the boat he was driving.
The court documents also show what investigators found on the boat, including 39 empty seltzer cans, two unopened seltzer cans, and also the heartbreaking discovery of a child's life jacket attached to the propeller of the boat.
The court documents also reveal what kind of vessel that Kight was driving, a 22-foot-long Tige boat.
Investigators say the boat is owned by Kight's girlfriend, AnneMarie Flanigan, who is also facing charges in the case and made a first court appearance Wednesday.
A 10-year-old Cary girl, Brooklyn Carroll, was killed.
Brooklyn's family released a new statement Thursday through their attorney, David Sherlin:
"Brooklyn was caring, funny, compassionate, and deeply sensitive. She had the biggest heart and an incredible gift for making others feel seen, loved, and included. Her greatest joy was bringing happiness to those around her - making sure no one ever felt left out.
"Her family, friends, and her dogs were her world. She had a uniquely goofy, wonderfully weird sense of humor that could brighten anyone's day, and it was a part of what made her so unforgettable. She always knew how to bring a smile to your face.
"She was the kind of person whose light made everything around her better. Everyone who knew her felt lucky to be a part of her life, and her memory will be cherished always."
Jennifer Stehle, 41, a wife, mother, and a social worker for the Wake County Public School System, suffered an amputation of the leg above the knee and was taken to UNC Hospitals in critical condition.
According to an online fundraiser for Stehle, she was in "great spirits" and scheduled to undergo more surgery on Thursday to repair broken leg bones.
Kight is charged with felony boating while impaired and misdemeanor boating while impaired.