BOSTON (CBSNewYork/AP) — Law enforcement sources said Wednesday that Pamela Geller, the New York woman behind a controversial contest this spring to draw the prophet Muhammad, was the target of a beheading in a terror plot that was foiled in Boston.

Alleged mastermind Usaama Rahim was killed by police Tuesday after he pulled out a knife and lunged at a police officer and a FBI agent in Boston.

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A second suspect, David Wright, was taken into custody Tuesday by officers in Everett, Massachusetts.

Sources said Rahim and Wright were ISIS supporters and were motivated by a desire to exact revenge on America.

The men were actively plotting multiple attacks on law enforcement, even including the possible beheading of police officers, the CBS source said, adding that the two were discussing attack plans on social media.

But Rahim was originally plotting to behead a private citizen in another state, according to court documents.

Sources said the original target was supposed to be Geller, a conservative activist and blogger who runs the New York-based American Freedom Defense Initiative.

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Geller’s group is known for mounting a campaign against the building of an Islamic center blocks from the World Trade Center site and for buying advertising space in cities across the U.S. criticizing Islam.

More recently, she organized the controversial event displaying drawings of the prophet Muhammad in Garland, Texas.

Geller told CNN she was not told of the specific threat, CBS Boston reported.

Rahim had been under surveillance by a Joint Terrorism Task Force and spreading online propaganda for ISIS well before he was shot and killed on Tuesday, said U.S. Rep. Michael McCaul (R-Texas), who chairs the House Homeland Security Committee.

Sources told CBS News that Rahim and Wright were communicating with each other about attacks in the U.S., which is why Wright was arrested. Authorities continued Wednesday to search for other people both Rahim and Wright were communicating with, the sources said.

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