Clark Perry Baldwin was born in Iowa on August 22, 1961, in Charles City by most accounts and in Nashua by another, and drove long-haul freight. A woman who had lived with him told a reporter afterward that she could not reconcile the gentle giant she had known with what he was accused of.
On March 10, 1991, the body of Pamela Rose Aldridge McCall, thirty-two, from Topping, Virginia, was found beside Interstate 65 at Spring Hill, in Maury County, Tennessee, about thirty miles south of Nashville. She was twenty-four weeks pregnant; the child she was carrying was named Angel. Skid marks on the road in front of where she lay showed that an unloaded tractor-trailer had locked its tires up at that spot, and those marks became part of the case against him. Prosecutors later said that around the same time another woman narrowly escaped from his truck.
On March 1, 1992, a woman driving her own rig stopped at the Bitter Creek turnout on the westbound side of Interstate 80, about forty miles east of Rock Springs, Wyoming, and found a young woman lying face down in the snow, strangled and unclothed except for a gold necklace and a gold wedding-style ring. Investigators called her Bitter Creek Betty, and for a rose tattoo traced to a shop in Tucson, Rose Doe. She was identified in May 2022 as Irene Vasquez, who had been reported missing in 1990, and the identification was announced in 2025.
In April 1992, Wyoming transportation crews checking a right-of-way fence off Interstate 90 near Sheridan found another young woman in a ditch, fully clothed except for her socks and shoes, also strangled and about three months pregnant. Accounts place the spot about fifteen miles north of Sheridan and about five miles south of the Montana line. She was called I-90 Jane Doe. On July 17, 2025, the Wyoming Division of Criminal Investigation identified her through a DNA match with her mother as Cindi Arleen Estrada, twenty-one, born in Torrance, California, on May 11, 1970, who may have been living in Long Beach. The two Wyoming bodies were found four hundred miles apart. Two of the three women were pregnant when they were killed.
In 2012 male DNA from the two Wyoming scenes was matched, showing one man had killed both. In April 2019 a Tennessee crime laboratory built a profile from evidence in the McCall case, ran it through the national database and matched it to the Wyoming profile. Three murders in two states were now one case, with no name attached to it. Later in 2019 genealogists using public genetic genealogy sites found a match to relatives in Iowa, and the list of possible suspects narrowed to members of his family.
The name came from his trash. In early 2020, having worked out where he was living, investigators watched him for several days and took away the bags he put out. They recovered saliva from scraps of food, extracted DNA and matched it. He was arrested at his apartment in Waterloo, Iowa, on May 6, 2020, and charged with all three killings. A detective who had worked the McCall case said that putting the handcuffs on him ended a long search.
Prosecutors in the two states agreed that he would be tried in Tennessee first and Wyoming second. The pandemic delayed the Tennessee trial repeatedly, and it did not end until May 5, 2025, when he was convicted of the first-degree murder of Pamela McCall and her unborn child and sentenced to life. Her mother had died before the verdict came.
He never reached Wyoming. His lawyers had filed for a new trial and no hearing had been held, and no extradition hearing had been set. He died of a heart attack in a Tennessee hospital on July 18, 2025, the day after Estrada was named. He was sixty-three. The Sweetwater County attorney, whose case for Irene Vasquez would now never be heard, said that they knew what had happened to her and knew who had done it.
Two further matters were reported and never charged. Court documents alleged that he raped and choked a woman in Texas in 1991. Iowa, Illinois and federal investigators also looked at other killings of women near highways in the same period for a possible connection, among them the 1992 death of Tammy Jo Zywicki, a Grinnell College student whose car broke down on Interstate 80 as she drove to school from Evanston, Illinois, and whose body was found in Missouri nine days later. Neither produced a charge. He was convicted of one murder, and his death left two others charged and never tried.