Mark Christeson
Credit: VINELink

ST. LOUIS (AP) — A Missouri man convicted of killing a woman and her two children in 1998 is asking state and federal courts to spare his life a day before his scheduled execution.

Mark Christeson is set for lethal injection at 6 p.m. Tuesday. If carried out, the execution will be Missouri’s first since May.

Among the issues raised in Christeson’s pending court appeals is that his trial lawyers were so inept they missed a 2005 deadline for a federal appeal.

Christeson was 18 when he and a 17-year-old cousin attacked Susan Brouk at her rural home in Vichy, then killed Brouk, her 12-year-old daughter and her 9-year-old son.

The cousins were caught after fleeing to California. Christeson’s cousin testified against Christeson and was sentenced to life in prison without parole.