A few hours before Rian Thal and Timothy Gilmore died in a hail of bullets outside Thal's apartment last month, the building's security cameras captured Thal and Gilmore talking with the three gunmen.

Police believe Thal and Gilmore had arranged a drug deal with the men, Philadelphia Capt. James Clark said yesterday. Sometime afterward, Thal and Gilmore, as well as the men, left the Piazza at Schmidts complex in Northern Liberties, where Thal had an apartment on the top floor of the ritzy Navona building.

Around 5 p.m. that day, June 27, the three gunmen and a lookout man returned to the Navona, allegedly aided by second-floor resident Katoya Jones. They were recorded by multiple cameras inside and outside the building as they staked out Thal's floor and waited for her.

Police believe the group had been instructed by another man to rob Thal, 34. After she was killed, police found four kilograms of cocaine and more than $100,000 in cash in her apartment.

Gilmore, 40, lived in Ohio and worked with Thal in dealing drugs, police said, and possibly used his trucking business as a front.

Police are searching for a local drug dealer who they believe set up the robbery. That man presumably knew Thal kept drugs and possibly money in her apartment. The robbery, however, went "just about as wrong as it could," Clark said.

Moments before the shootings, three men hid in the stairwells around Thal's seventh-floor apartment as the fourth kept a lookout from the sixth floor. When Thal and Gilmore returned, cameras caught them as they got off the elevator and started walking toward Thal's apartment, then stopped as if they thought something felt wrong. Thal even turned around and looked out the window before she and Gilmore resumed walking.

That's when three armed men appeared from either end of the hall, trapping Thal and Gilmore between them. Security footage shows that words were exchanged, then Gilmore may have tried to make a break for it, said Philadelphia Lt. Philip Riehl. The men opened fire, killing Thal and Gilmore, then left without taking anything.

"Once you fire shots on a seventh-floor hallway, people are going to hear that and call the police," Clark said. "With that going on, you've got to get out of there as fast as you can."

The four men left the building quickly and have not been found. Fingerprints left in some areas of the building are still being processed, Riehl said.

Jones, 25, was arrested five days after the killings and charged with murder, conspiracy, and other offenses. She was scheduled to be arraigned this week, but her appearance has been postponed until next month.

An associate of Gilmore's was inside Thal's apartment during the shooting, Clark said, and left quietly afterward. Cameras captured him exiting the apartment with a duffel bag, possibly containing drugs.

That man, who is also being sought by police, was involved in that day's drug transactions, Clark said, but police do not believe he had anything to do with the shootings.

Contact staff writer Allison Steele at 215-854-2641 or asteele@phillynews.com.