Detective Sergeant David Speight says whoever caused the fires may have flash burns on their body.
Michael and Angela Broderick, who are both deaf, had a narrow escape when an arsonist destroyed their home in Burbage in Leicestershire.
Police are appealing for the public to contact them if they have any information.
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Jay Crouch received five new organs - two kidneys, a liver, small intestine and pancreas.
Outbreaks of rain spreading from the west overnight.
Cloudy this evening, with outbreaks of rain moving in from the northwest.