A couple jailed for killing a toddler were allowed to adopt despite concerns about their commitment and motivation.
The boy was found comatose at Ian and Angela Gay's house
One foster carer warned Ian and Angela Gay of the work involved in bringing up a child from a troubled background.
The carer was then shocked when Ian Gay said he did not mind as long as there were "rewards".
Mrs Gay's parents described her after the trial as the "perfect mother", yet the boy was dead only six weeks after moving in with the couple.
The pair, from Halesowen, West Midlands, were convicted on Thursday of poisoning Christian Blewitt with salt and causing him a fatal head injury.
The trial judge, Mr Justice Pitchers, said they were "intelligent enough" to give the impression to social services that they would be proper carers.
But he told Mrs Gay: "Your decision to go to work as Christian lay desperately ill in hospital showed where your priorities lay." Experts could not agree about how Christian sustained the head injury from which he died, despite the wealth of medical evidence in the case.
Ian Gay had described Christian Blewitt as a "zombie"
Doctors found he had excess levels of sodium in his blood. One expert calculated it was the equivalent of 40 grams (nearly an ounce and a half) of salt - and that he had suffered brain damage.
Post-mortem examinations discovered 11 areas of "sub-scalp" bruising and the cause of death was given as blunt force trauma.
Home Office pathologist Professor Helen Whitwell said the fatal brain damage could have been caused by an impact, or forceful gripping.
Prof Whitwell said there was "nothing specific" to indicate the bruising to the brain had been caused by too much salt and there was no evidence of a weapon being used.
Home Office pathologist Dr Peter Acland, who conducted a second post-mortem examination and appeared for the defence, said he did not consider the head injury was caused by a deliberate impact.
When the youngster was found comatose at the Gays' home in Bromsgrove, Worcestershire, in December 2002, Mr Gay drove him 27 miles to Russells Hall Hospital in Dudley even though the A&E department at the Alexandra Hospital in Redditch was nearer. Mr Gay had told police his wife wanted to send Christian back in the week before he collapsed.