A 19-year-old Shoshone man whose mother is in prison for plotting to kill her former father-in-law was badly injured in a "fight club" boxing match.

The Times-News reports Blue Haddon suffered a head injury Monday evening. He was initially hospitalized in critical condition, but was upgraded to serious by Tuesday night.

A 25-year-old man, William Greener, was arrested on suspicion of battery. Greener said Haddon had fallen backward after being punched.

Hadden's mother, Traci, is serving 10 to 15 years in prison after conspiring with her son's 16-year-old friend to shoot Craig Hadden in 2009. Blue Hadden told the newspaper last year that his mother had tried to pressure him into shooting his grandfather for the inheritance money.

His friend was convicted of attempted murder and sentenced to up to 10 years in prison.