On Thursday, police charged 24-year-old Alexander Solomon with carjacking the vehicle involved in Monday night's shooting of Corey White, 22.
White's ex-girlfriend, London Eley, has been jailed for weeks on charges she used Facebook to try to find someone to kill him. The same day White was killed, a judge upheld felony charges against Eley and 18-year-old Timothy Bynum.
Eley, 19, has been fighting with White over custody of their young daughter, among other things, police said.
"I will pay somebody a stack to kill my baby father," she allegedly wrote in May, using slang for $1,000.
The 18-year-old Bynum allegedly posted: "Say no more ... what he look like ... where he be at ... need that stack 1st."
Both have been in jail since their arrests in early June, and remained so after Monday's hearing. Defense lawyers insist neither was serious about the hit.
Police were startled when White - only hours after Eley's and Bynum's court hearing - was gunned down near his home by someone stepping out of a stolen brown car.
The vehicle had been carjacked at 7:30 p.m. Monday from two moviegoers in Upper Darby. White was killed about 40 minutes later a couple miles away in neighboring Philadelphia.
"White apparently was trying to sell this group bad drugs, a confrontation occurred and White got shot," Upper Darby Police Superintendent Michael Chitwood told the Associated Press.
On Thursday, Upper Darby police charged Solomon of Upper Darby, with stealing the car at gunpoint. Solomon is charged in three recent carjackings, all of them at gunpoint, and with stealing a fourth car left running by someone using an ATM.
Solomon was being held on $3.25 million bail while Philadelphia detectives continued to investigate the homicide and Upper Darby police sought other carjack suspects.
Upper Darby police had been trying to find White in recent weeks to discuss a July 18 killing outside a nightclub. They had heard White drove the getaway car.
Philadelphia Homicide Capt. James Clark said his department has not made a final determination on whether White's slaying was motivated by drugs, the nightclub slaying or the Facebook plot.
"We're still exploring every avenue of why he was killed," Clark said Thursday.