In this position, Riker abused the Fugitive Slave Act to send free blacks to the South to be sold into slavery.

By the 1830s, abolitionists considered Riker a member of the "Kidnapping Club",[3] along with Daniel D. Nash and Tobias Boudinot, who "boasted that he could 'arrest and send any black to the South.

'"[4][5] In 1828, Riker was also made the subject of a satirical poem, "The Recorder" by Fitz-Greene Halleck, which mockingly compared him and other members of the New York party machine to classical figures like Julius Caesar.

[8] The island's name has been the subject of some controversy, and has drawn comparisons between Riker's kidnappings and the disproportionately African-American population of the jail.

[7][4] In 1813, Riker became one of the six founding members of the Supreme Council, Scottish Rite, Northern Jurisdiction, a branch of Freemasonry.