Smit assessed the evidence and concluded that an intruder had committed the crime. On the night JonBenét was killed, there had been two windows that were left slightly open to allow for electrical cords for the outside Christmas lights to pass through, a broken basement window, and one unlocked door. Smit's theory was that someone entered the Ramsey home through the broken basement window. This has been criticized because there was an intact cobweb in the basement window. The steel grate that covered the window also had undisturbed cobwebs, and the foliage around the grate had been undisturbed. There were also cobwebs in the tracks of various windows, and dust and debris were on some sills. Smit believed that the intruder subdued JonBenét using a stun gun and took her down to the basement. JonBenét was killed and a ransom note was left. Smit's theory was supported by former FBI agent John E. Douglas, who had been hired by the Ramsey family. Believing that the Ramseys were innocent, Smit resigned from the investigation on September 20, 1998, five days after the grand jury was convened against the Ramseys. While no longer an official investigator on the case, Smit continued to work on it until his death in 2010.