Steven Brian Pennell

Steven Brian Pennell (1957 or 1958 — March 14, 1992), aka The U.S. 40 Killer, was convicted of the murders of two New Castle County, Delaware women and suspected of three more. Pennell, an electrician by trade, picked up his victims in his van along U.S. 40 near Bear, a corridor known for prostitution activity.

Pennell was arrested November 29, 1988 for the June 1988 murders of two Newark, Delaware women, Shirley A. Ellis, 23, in November 1987, and Catherine A. DiMauro, 32, in June 1988. Pennell was identified as the suspect by carpet fibers found on a victim's body; the fibers were from a carpet located on the floor of his van. He was convicted in November 1989, but the jury deadlocked on the death penalty vote; he was sentenced to life for these crimes in a 1990 trial.

Prosecutors were preparing to try Pennell for the murders of Michele A. Gordon, 22, of New Castle County, and Kathleen Anne Meyer, 26, of Newark, in September 1988. Pennell suddenly pled no contest, on the condition that he receive the death penalty. His plea of no contest to the murder of Kathleen Meyer in 1991 arose once DNA evidence linked him to the case.

Pennell was also suspected of the August 1988 murder of Margaret Lynn Finner, 27, but the decomposition of the body hampered their ability to develop sufficient evidence.

Pennell was the first condemned man to argue his own case before the Delaware Supreme Court. Pennell argued to affirm the death penalty. Although he never admitted guilt, his rationale was "to spare his wife and two children the prolonged pain of his spending the rest of his life in prison." The court affirmed the sentence.

He was executed on 14 March 1992 by the State of Delaware by lethal injection. He became the first person to be executed in Delaware since 1976, when the death penalty was reinstated, and the first person executed in Delaware since Forest Sturdivant, a murderer, was hanged in 1946. He was the state's first and to date only confirmed serial killer.