According to the report, the brothers told witnesses their plans to rob the apartment of 23-year-old twin sisters Kayetie Melchor and Rebeika Powell. The sisters lived in apartment 1421, a few doors away from James Poore's listed residence.
James Poore also told witnesses both he and his brother shot the twins, along with Misty Nunley and Julie Jackson, who were also in the apartment at the time, the report states.
The women, each with their hands bound behind their backs, died from gunshot wounds to the head.
The Poore brothers took drugs, money and jewelry from the residence, according to the affidavit.
A search warrant of Cedric Poore's Tulsa home also reportedly uncovered spent .40-caliber shell casings in his backyard, matching those found near the victims' bodies.
During an interview of James Poore following his Wednesday morning arrest, the 32-year-old told investigators he knew at least one of the victims and had been in the apartment where the murders happened, but did not confess to the crime.
Cedric Poore denied being in the apartment that day.
During Wednesday's press conference, Tulsa police chief Chuck Jordan said first-degree murder charges are expected to be presented to the District Attorney's office Thursday.