"Obviously this is something we're going to look at really strongly, as far as a possible reason why Mr. White was killed," Clark said. "However, there are a couple of theories out there."
One of those theories, investigators said, involves White's alleged role in an Upper Darby shooting last month. Another is that the slaying was related to drugs.
About 7:45 p.m., White, 22, was shot twice in the chest on the 5100 block of Hadfield Street, just blocks from where he lived, police said. He died shortly afterward at the Hospital of the University of Pennsylvania.
Earlier Monday, Municipal Court Judge Patrick Dugan held White's ex-girlfriend, London Eley, 19, of Upper Darby, and Timothy Bynum, 18, of Darby, for trial on charges of criminal solicitation for murder and attempted murder.
Authorities allege that Bynum and Eley conspired to kill White in a series of Facebook posts in May.
In May, after an argument with White, Eley allegedly posted on 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!"
Bynum, police said, responded with: "say no more. what he look like. where he be at. need that stack 1st ima mop that bull."
Officers found a .22-caliber handgun in Bynum's apartment.
White testified against the pair at a hearing two weeks ago. Both have been in custody since their arrest.
Gerald Stein, Eley's defense attorney, argued that his client was angry when she made her Facebook posts but that she came to regret her statements.
"She started spouting off, and venting, and unfortunately she did it on the Internet," he said. "But if everybody who said 'I want to kill this person' was arrested, we'd have to build 10 more jails in Philadelphia."
Eley heard of White's death Monday night, Stein said.
"She was distraught," Stein said. He said he did not believe White's death was connected to the Facebook statements.
Bynum's attorney could not be reached for comment.
Since the investigation is open, the District Attorney's Office could not comment on whether White had sought witness-protection services from the office, said spokeswoman Tasha Jamerson.
White might have been a target for his involvement in a deadly shooting in Upper Darby, investigators said.
Police believe White was with John Gordon, 37, of Southwest Philadelphia, when Gordon allegedly fired 13 shots outside the Venue bar on Garrett Road about 2:40 a.m. July 18, said Upper Darby Police Superintendent Michael Chitwood.
There had been a fight in the bathroom, and Gordon, who had served 10 years for murder, allegedly yelled to the crowd: "You need to get out of here; it's about to be a [expletive] crime scene."
A 23-year-old man died in the gunfire.
Police believe White drove the getaway car, Chitwood said.
"We were trying to find him for questioning," Chitwood said of White. "But we didn't find him until he turned up dead."
Police say they believe the actions leading to White's death began about 7:30 p.m. Monday, when a motorist was carjacked near 69th and Chestnut Streets in Upper Darby, police said. The brown car taken was the one used in the White shooting, investigators said. It was later found torched in Yeadon.
Fifteen minutes after the carjacking, police said, two or more men pulled up as White was hanging out on Hadfield Street, just down the block from the Hide-a-way Bar.
One man got out of the car, words were exchanged, and the man shot White, police said.
Hadfield Street is a dangerous block, said Keith Brown, 50, who runs an auto-repair shop on the corner. There have been other recent shootings and killings on the street, he said.
White had a DUI arrest in July but no other criminal record, according to court records.
White was a victim of a gunpoint robbery in 2008, according to court records, and he identified his attacker. The robber is still in prison.
He lived with his mother and two sisters in a rowhouse on Webster Street. His family declined to talk with reporters Tuesday.
Neighbors remembered him as respectful, quiet, and well-mannered.
"He was a friendly guy. He wasn't out here bothering nobody," said Larry White, a neighbor who is not related to Corey White. He said Corey White had recently asked him if he could work in his construction business.
"I told him if I needed an extra hand, I'd bring him in," Larry White said.
Corey White was often seen with his 3-year-old daughter, Serenity, whom he had with Eley.
"That little girl was his life," said neighbor Karen Mobley.
Neighbors said White's mother, Tashanika White, had been driving with Serenity when she turned onto the street Monday and was told that her son had been killed.
"She just broke down, crying uncontrollably," Mobley said. "Some of the men had to carry her inside. I held the little girl."
Contact staff writer Mike Newall at 215-854-2759, firstname.lastname@example.org, or @MikeNewall on Twitter.