If I'm remembering the case correctly, the only phone call was when she talked to her friend from Seattle, WA. that night. I think the friend came forward and told police. I don't recall them ever stating in the news that they had checked her phone records. There has been speculation as to whether or not the phone company kept or had the ability to keep or know what the phone records were for private residences back then. Someone might help clarify this one.
There was two phone calls that night and the second phone call the police have never said who Sherill was speaking to.