"The man who drove the car into the building has been in a mental breakdown," the caller said. "I know him personally and I think he did it on purpose, and it was his family that he drove the car into."
Roger Self is now facing murder charges.
Police said he took his family into the Surf and Turf Lodge over the weekend. Once they were seated, he then excused himself, went out to his vehicle and drove it at a high rate of speed into the area where they were sitting.
Self's daughter Katelyn, 26, was one of the victims killed. She was a Gaston County sheriff's deputy.
The other victim was identified as Amanda Self, Roger Self's daughter-in-law, according to the family's pastor, Austin Rammell.
Other family members were also injured, according to police, including Amanda Self's 13-year-old daughter and Roger Self's wife, Diana.