"No, but I got this," Alston allegedly responded, pointing a handgun.
He then sped off, police said, beginning a 15-minute pursuit through six neighborhoods during which he drove on the wrong side of Broad Street and pedestrians had to jump out of the way. It ended when Alston, driving east on a westbound street, smashed the VW into a 1995 Honda Accord at 10th and Ontario Streets.
A man in the passenger seat of the Accord, whom police had not yet identified, was pronounced dead at the scene. The driver, a 26-year-old woman, was in critical condition at Temple University Hospital, police said. The 4-year-old was in critical condition with head trauma at St. Christopher's Hospital for Children but was expected to survive.
Alston was charged with murder and related offenses. Police are investigating whether he had committed other crimes that might have led him to pull the gun when officers approached him.
But it's possible he just didn't want to go back to jail. In March 2011, he was sentenced to a year in prison on a drug-possession charge. His release date was not clear from court records.
Like many police departments across the country, Philadelphia's in recent years enacted stricter pursuit policies because of the risk of accidents and injury to bystanders, police spokesman Lt. Raymond Evers said.
Nationwide, between 300 and 500 people are killed every year in police chases, according to varying studies. A 2010 USA Today review found that about one-third of those killed in such pursuits were bystanders.
Philadelphia revamped its policy in 2008, Evers said. Car pursuits are prohibited in cases of motor vehicle theft, traffic violations, and DUIs, he said, though they are considered justifiable when there is probable cause that a suspect has committed a "forcible felony" - murder, rape, or armed robbery - or is carrying a deadly weapon.
"The individual pointed a gun at the officers, and that gave them reason to pursue," Evers said.
When engaging in pursuit, officers are required to immediately notify the dispatcher of the reason for the chase, and their direction, speed, and road conditions. A supervisor monitors the pursuit, deciding whether it should continue.
Friday's pursuit was overseen by a police helicopter pilot giving turn-by-turn updates to officers. After the crash on Ontario Street, Alston ran to a junkyard, where he was apprehended.
Like all police-car chases, the pursuit will be investigated, Evers said. "The commissioner will look very closely at the actions of the officers and the supervisors to see what exactly was done and that it was correct," he said.
Contact staff writer Mike Newall at 215-854-2759 or firstname.lastname@example.org.