Police called him "the big guy." He showed up in June in a hallway at the Piazza apartment complex in Northern Liberties, where surveillance cameras captured him stepping over two bodies: those of Rian Thal and Timothy Gilmore, who just moments before had been gunned down outside Thal's door.

He had been inside Thal's apartment that day, waiting for Thal and Gilmore to return, when he heard a rapid pow! pow! pow! on the other side of the door. He looked out the peephole and saw Thal's body on the floor, he told police.

"I started panicking," he told police in an interview in September. "I knew they were going to come in her apartment, and I just didn't want to die."

According to documents made available to The Inquirer, "the big guy" is Edward Emerson Jr., 41, a long-haul trucker from Texas - and a convicted robber and drug dealer - who traveled to Philadelphia with Gilmore after they unloaded a shipment of beer in Maryland.

Gilmore planned to buy drugs to take to Detroit, Emerson told police in a statement taken in Texas, where he is imprisoned on charges of violating his parole.

But before they could leave town, the 40-year-old Gilmore and 34-year-old Thal, a party promoter who police said dealt drugs, were killed by three gunmen who ambushed them outside Thal's seventh-floor apartment in one of the most sensational crimes of the year.

After the gunfire, Emerson wasted little time. He found no place to hide in Thal's apartment, so he sneaked into a neighbor's apartment using a terrace shared by the two units. There he waited, with the neighbor's small white dog "barking and screaming" at him.

"I was so scared I was crying," he told investigators.

Soon, he was in a cab headed west on the Pennsylvania Turnpike, a ride that lasted three hours before a friend picked him up at an exit.

At one point, he said, state troopers stopped the cab, but let the driver go without a ticket. At the time, police were not seeking him.

But even before the Philadelphia murders, the Drug Enforcement Agency was investigating Emerson, according to police sources.

Records show he was sentenced to five years in 1991 on a 1985 robbery charge, and he was convicted in 1994 and 1997 of drug dealing. He was sentenced in 1997 to a maximum of 13 years, according to prison records, but was apparently paroled sometime in the last few years.

Emerson is being held at a Houston-area prison for parole violators; the circumstances surrounding his latest arrest were not clear.

Police have said that Will "Pooh" Hook, 41, an alleged drug dealer, arranged for the gunmen to rob Thal, but that the plan went sour. Police later found more than $100,000 and eight pounds of cocaine in her apartment.

Eight people have been arrested in connection with the June 27 murders, including Hook, a man accused of acting as a lookout for the gunmen, and a woman who let the gunmen into Thal's building.

The Philadelphia District Attorney's Office is deciding whether to seek the death penalty against Hook and the three alleged gunmen.

Police do not believe Emerson had anything to do with the shootings, but investigators searched for him for weeks in the summer before finding him jailed in Texas.

"He was a witness who obviously had to be interviewed," said Philadelphia Lt. Phil Riehl, who has led the investigation. "He was a missing piece of the puzzle."

Gilmore, a former Detroit firefighter who lived in Ohio, has been described as a drug dealer who used his trucking business for dealing on the side. He was arrested in 2007 in Newark, N.J., after police caught him with five ounces of hydroponic marijuana.

As the murder case has moved into the court system, differing accounts of the events have emerged. Donnell Murchison, 33, accused of being the lead gunman, has told investigators that Thal had helped set up the robbery, presumably so she would receive a kickback in drugs or money.

Hook's lawyer, Christopher Warren, has said Hook is innocent and disputes Murchison's account.

Some of the alleged gunmen have said that they believed Gilmore and Emerson were Thal's suppliers, and that the robbery was organized around their visit.

Emerson's account contradicts that. He told police that he and Gilmore had delivered Budweiser beer in Maryland on the Tuesday before the Saturday evening shootings, and that Gilmore had convinced him that they could make money from a drug buy if they stopped in Philadelphia before heading west.

"He said that there was a drought in Detroit," Emerson told police. "So I kinda knew then that he was talking about a possible drug thing."

Emerson said he had gone along with it because he had been having financial problems.

"If what he was saying was true, it was worth the risk to me," he said.

They arrived in Philadelphia that Wednesday, and were met by a man who had keys to Thal's apartment and knew the security code to enter her building, Emerson said. The man went into and came out of Thal's apartment several times each day, and each time he would go with Gilmore and Thal into her bedroom to talk.

"I'm not stupid. I knew they were doing something, but they were keeping me in the dark," Emerson said.

Riehl would not comment on whether Emerson's account of his role in the drug dealing is credible, saying, "It's irrelevant to the case."

Emerson told police that he had mostly stayed in the apartment while in Philadelphia. The night before the murders, a Friday, he and Gilmore went to Club Onyx, a strip club on Columbus Boulevard in South Philadelphia. Other times, Emerson said, he surfed the Web for porn on Thal's computer.

The afternoon of the murders, Thal and Gilmore went to a Western Union, Emerson said. He said he had expected that he and Gilmore would leave when Gilmore got back, and he called his wife to tell her he would be coming home soon.

Then the ambush went down.

When Emerson went to the neighbor's apartment, he took with him a duffel bag that he said contained his clothes. Security cameras captured him carrying the bag, which police have speculated contained drugs, out of the building.

He told police that he had a female friend meet the cab somewhere along the turnpike. She drove him to her house in Cleveland, and from there, he said, he flew back to Texas.

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