Ebony Dickens of East Point, Georgia, posted her Facebook rant under the name Tiffany Milan, police said.
"All Black ppl should rise up and shoot at every white cop in the nation starting NOW," said the post made on Monday. "I condone black on white killings. Hell they condone crimes against us."
The post was removed a day later, just before Dickens was arrested, CNN affiliate WSB reported
"I thought about shooting every white cop I see in the head until I'm either caught by the police or killed by them. Ha!!!! I think I can pull it off. Might kill at least 15 tomorrow, I'm plotting now."
Needless to say, it got law enforcement's attention. Not only the East Point police, but Atlanta police -- whose homeland security unit "worked diligently ... to identify the true identity of the poster and her whereabouts," said Atlanta police spokeswoman Elizabeth Espy -- as well as the FBI and federal Homeland Security Department.
"That's 15 people that she's talking about killing within a day or so, so whether she is serious or not that's something that we have to take seriously," East Point police Lt. Cliff Chandler told WSB.
Police in East Point -- a city of about 34,000 people just south of Atlanta -- said in a statement that, in addition to detailing how many police might die and threatening white officers specifically, the posts "indicated that the acts were being plotted and were in motion."
After connecting Dickens to the Facebook post, authorities obtained a search warrant for her residence.
They took her into custody while executing that warrant. "A firearm along with three computers was located during the search," East Point police said.
Dickens, 33, appeared in court Wednesday on a charge of disseminating information related to terrorist acts. A judge set a $10,000 bond for her and banned her from social media.
She was then transferred to Fulton County Jail, where she remained until bonding out at 6:19 a.m. Thursday, according to county sheriff's office spokeswoman Tracy Flanagan.