joseph sobel, who studied the weather patterns on the night of the murder. >> dew is moisture, condensationthat forms on the object we're talking about, whether it be a blade of grass, a rooftop or car top or any object that happens to be outside during that time. >> the temperature on the afternoon of the murder was 70 degrees, so the dew point temperature, the point when water in the air becomes cold enough to change from a gas to a liquid producing dew, would have occurred when the temperature reached 50 degrees. >> we know the night was clear. surface weather observations showed us that. we know it was very cool, so that the temperature was able to drop considerably and we know that there was little or no wind. >> the temperature hit 50 degrees at 11:00 p.m. glenn wolsieffer said he drove home at 2:30 in the morning, yet there was no dew on his car when police arrived at 7:00 a.m. if he had driven home at 2:30 in the morning, glen's car would have had the same amount of dew as his wife's car. the lack of dew meant someone had driven glen wolsieffer's car sometime after glen returned hom