Updated

Five legal groups are supporting a Missouri death row inmate, whose execution was halted hours before it was to be carried out in 2014, saying that he can't receive an adequate defense with the money allocated.

Three national criminal defense associations, a civil rights law firm and the American Bar Association made court filings last week to the 8th U.S. Circuit Court of Appeals in St. Louis on behalf of Mark Christeson, convicted of the 1998 killings of a Missouri woman and her two children.

The U.S. Supreme Court halted the execution because Christeson's original trial attorneys missed the federal appeal deadline. Virtually all capital cases are appealed through the federal courts.

New lawyers were appointed, but a district court provided only $10,000 of the $161,000 sought.

The new attorneys can't afford to bring in experts to testify that Christeson's mental impairment left him unable to assert his own rights when his trial lawyers failed to adequately do their job, the defender groups said.

Janet Moore, co-chair of the Amicus Committee for the National Association for Public Defense, said in a statement Monday that failure to provide adequate funding for indigent capital defendants has "created an untenable system, where counsel are unable to satisfy constitutional and ethical demands."

Christeson was 18 in 1998 when he and a 17-year-old cousin, Jesse Carter, decided to run away from a home outside Vichy, Missouri, where they were living with a relative. They walked a half-mile to the neighboring home of Susan Brouk, armed with shotguns, planning to steal her Ford Bronco.

But once there, they used shoelaces to tie the hands of Brouk's two children. Christeson forced Brouk into a bedroom and raped her. They drove the family to a pond where Brouk and one of the children were stabbed and thrown into the water to drown. The other child suffocated when Christeson pressed on her throat while his cousin held her.

Christeson and Carter fled to California, where a detective recognized them from photos police distributed and arrested them. Carter agreed to testify against Christeson and was sentenced to life in prison.

The ABA filed in support of Christeson on Wednesday. A similar brief was filed Friday by the National Association for Public Defense; the National Association of Criminal Defense Lawyers; the National Legal Aid and Defender Association; and the Roderick and Solange MacArthur Justice Center of St. Louis. The Missouri attorney general's office declined comment.