A German man who called himself Clark Rockefeller and who spun fantastic stories about his past is appealing his sentence for kidnapping his 7-year-old daughter in Boston.

Christian Karl Gerhartsreiter is expected to appear before a tribunal in Suffolk Superior Court on Wednesday.

Gerhartsreiter was sentenced to four to five years in prison last year for kidnapping his daughter in 2008. They were found in Baltimore and the girl was unhurt.

Defense lawyers argued Gerhartsreiter was legally insane.

Gerhartsreiter used multiple aliases to move in wealthy circles in Boston, New York and Los Angeles after coming to the U.S. in the 1970s. At times, he claimed to be a physicist, an art collector, a ship captain and a financial adviser.