Pamela Geller
Pamela GellerReuters

A Muslim who was fatally shot on Tuesday after waving a military knife at law enforcement officers in Boston was originally plotting to behead Jewish blogger Pamela Geller, law enforcement sources told CNN on Wednesday.

However, Usaamah Rahim, a 26-year-old security guard who officials believe was radicalized by ISIS and other extremists, decided instead to target the "boys in blue," a reference to police, according to court documents.

"I can't wait that long," he said of the original beheading plan, according to an FBI affidavit filed in federal court in Boston on Wednesday.

Gelller, the founder and president of the American Freedom Defense Initiative (AFDI), is known for her campaign against extremist Muslims, which has featured among other things prominent bus ads criticizing Muslim anti-Semitism.

Geller drew national attention last month after an off-duty police officer thwarted an attack at her organization's contest for Prophet Mohammed drawings in Garland, Texas.

"They targeted me for violating Sharia blasphemy laws. They mean to kill everyone who doesn't do their bidding and abide by their law voluntarily," Geller told CNN's Erin Burnett at the time.

"This is a showdown for American freedom. Will we stand against this savagery or bow down to them and silence ourselves?" added Geller, who said that she's had an "army of security" since last month's thwarted attack.

"This is what is required just to show a cartoon in America, 2015," she said. "It's striking. It's devastating, and people need to understand what's at stake. I mean, if we surrender on this point, what will we surrender next?"

According to CNN, about two hours before Rahim's confrontation Tuesday with officers on a Boston street, he allegedly told an associate he was "going to ... go after them, those boys in blue. 'Cause ... it's the easiest target," the documents say.

Rahim's alleged associate, David Wright, 25, appeared in a Boston court on Wednesday to face a charge of obstructing a federal investigation by destroying electronic evidence on Rahim's smartphone.

A detention hearing was scheduled for June 19 after prosecutors said he was a flight risk, the report said.

Wright allegedly attempted to destroy co-conspirator Rahim's cell phone and conceal evidence of their plans, according to the documents. He faces a maximum penalty of five years in prison if convicted.