Prosecutors in the US believe a young couple from Missouri put their four-month-old infant in a microwave.
Derick Boyce-Slezak and Mikala Boyce-Slezak have been charged with abuse or neglect of a child, reports local newspaper the St Louis Post-Dispatch.
The couple, both 22, took the boy to hospital in April saying he had a rash on his face. Testing showed the rash was actually a second-degree burn, and he also had a skull fracture and a brain injury.
They claimed a cleaning agent caused the burn, but Mikala is alleged to have told a health official Derrick had dropped the baby while imitating a TV commercial, and she believed he'd also put the boy in the microwave for a "short period of time".
The couple have previously had a baby girl, whom they handed over to social services in January 2016. It's not known why.
They remain in jail on a US$500,000 bond.