Baltimore ? A man accused of kidnapping his 7-year-old daughter during a supervised visit in Boston last weekend was arrested Saturday in Baltimore and the girl was found safe, authorities said.

A “concerned citizen” tipped off authorities that the man known as Clark Rockefeller was living in a Baltimore apartment and had a 26-foot catamaran sailboat docked at a nearby marina, Boston Police Commissioner Ed Davis said.

Rockefeller will be arraigned Monday to begin extradition proceedings.