On December 24, 1987, Grace Kehler returned home in Fort Worth, Texas, to find 26-year-old Michael Trekell (born March 27, 1961), with whom she lived, and their infant son Jayson (born August 1987) dead, the deaths ruled homicides by forensic investigators.

[1] Bigby murdered two other men, Wesley Crane and Frank "Bubba" Johnson, the same day he killed the Trekells, but was not charged in either of their deaths.

After the defense rested its case, the judge allowed the rebuttal by the state to introduce testimony regarding Bigby's stealing the gun and threatening the judge, portraying the incident as attempted escape, and further saying this was evidence that Bigby was conscious of his guilt and therefore not eligible for the insanity defense.

The jury's verdict found Bigby guilty of capital murder in a double homicide and imposed the death penalty.

[1] Bigby's case went to a retrial in September 2006 (double jeopardy did not apply, as the ruling did not acquit him outright), where the jury imposed the same death penalty that their counterparts had 15 years previously.

[4] Thus the court struck down jury instructions in death penalty cases that do not ask about mitigating factors including a consideration of the defendant's social, medical, and psychological history, saying that the jury must be instructed to consider mitigating factors even when answering unrelated questions.