NAPERVILLE, Ill. (AP) — A suburban Chicago man has been charged with first-degree murder in his wife’s March death after a police investigation found that he allegedly kicked her repeatedly during a fight.

Fifty-six-year-old Alan Wang of Naperville was initially charged with aggravated domestic battery in connection with the March 8 death of 35-year-old Hongyan Yang.

The DuPage County state’s attorney’s office says that charge was upgraded to first-degree murder after a police investigation determined that Wang had been fighting with his wife the night before and had kicked her multiple times.

An autopsy also found that she died from internal bleeding.