"We believe there was a real potential for him to carry it out," said Lt. John Walker of the Southwest Detective Division. "He had the means to make it happen."
Bynum is charged with attempted murder, conspiracy, and related offenses. Eley was arrested Friday and charged with conspiracy to commit murder.
Police said the plot was hatched in late May, when Eley got into an argument with ex-boyfriend Corey White of West Philadelphia and posted to her Facebook wall: "I will pay somebody a stack to kill my baby father." "Stack" is slang for $1,000.
When several people commented, one asking if she was sure she wanted White dead and not just hurt, police said she posted, "DEAD! HATE HIM."
Next, police said, Bynum responded with "say nomore wat he look like nd where he be at." After Eley gave a description and information about where White was, Bynum indicated that he needed to be paid first.
White's relatives saw the exchanges on Eley's page and immediately told White, who called police, Walker said.
"Upon reading the messages, he was extremely shaken by them," Walker added.
Along with the exchanges between Eley and Bynum, investigators found photographs on Bynum's page that depicted him displaying guns.
No more messages have been posted on the wall since May, but police said they do not know whether the two continued the discussions via private messaging or e-mail. Authorities could find no sign that any money had been exchanged, Walker said.
Bynum and White do not know each other, Walker said, and police are not sure whether Bynum and Eley even know each other.
"Who knows what [Eley's] end motivation was?" Walker said. "But the words were what they were."
Contact staff writer Allison Steele at 215-854-2641 or asteele@phillynews.com.Staff writer Mari A. Schaefer contributed to this article.