The judge's decision Wednesday paves the way for prosecutors to seek the death penalty against 42-year-old William Smithson of Glen Mills.
The judge also declined to grant immunity to a potential defense witness.
Smithson is charged with killing 23-year-old Jason Shepard of Cavalier, N.D., who was interning for Daktronics Inc. Shepard was found dead in Smithson's home. A trial is expected this spring.
The judge says a jury could find aggravating circumstances to support the death penalty.
