On Wednesday evening, the young men, stepbrothers, had growing criminal histories and outstanding arrest warrants.

Then, in less than 15 minutes, police allege, 18-year-old Donta Cradock and Ivan Rodriguez, 20, graduated from stealing a motorcycle at gunpoint to murder in a horrific car crash that stunned a Feltonville block with the split-second end of the lives of a young mother and three children.

Though separated two years ago when Cradock was sent to a juvenile facility in Pittsburgh after an armed holdup in Philadelphia for a pack of beer, they appear to have been reunited - illegally - two months ago when Cradock disappeared April 15 while home on a pass.

Since then, Cradock seems to have remained in the area despite a bench warrant for his arrest. Rodriguez was also on the lam - wanted after he failed to appear June 2 for a preliminary hearing on charges involving a stolen car.

Now each will be charged with four counts of murder, and Feltonville neighbors and public officials want to know how two men with troubling criminal records remained at large.

Among them is Cradock's mother, Vanessa Cradock, who said she also raised Rodriguez. In an interview with NBC10 news, she said she had called her son's probation officer after he failed to return to Pittsburgh when his pass expired.

No one came to pick up the wayward 18-year-old.

Police Capt. James Clark, head of the homicide unit, told reporters yesterday that Cradock and Rodriguez are "well-known to police."

Most of their arrests are not public record because they occurred when the two were juveniles. But police said yesterday that Cradock had eight arrests - five involving firearms - and Rodriguez five, many involving stolen vehicles or stolen car parts.

Police said the .357 Magnum revolver used to steal the motorcycle was found in the wrecked Pontiac with Cradock.

Police said that after Rodriguez was arrested at his home, a search of his house yielded a 20-gauge sawed-off shotgun, a 7 mm hunting rifle, and a pellet rifle.

Cradock's one arrest in public court records occurred April 2, 2006, and involved charges of robbery, conspiracy, firearms violations, and related counts. Because of his age, the case was referred to Family Court.

Court system sources say the robbery involved the stickup of a pedestrian for an eight-pack of beer.

A police spokesman, Lt. Frank Vanore, said Cradock's record goes back to about age 12 and includes one incident that ended in a car crash.

Cradock, who police said drove the car that crashed, was hospitalized but expected to recover. He lived in the 300 block of East Rockland Street, about five blocks northeast of the crash site, on Third Street near Annsbury Street.

Clark said Rodriguez was arrested Wednesday night at his home in the 4100 block of North Eighth Street, about five blocks to the southwest in Hunting Park.

The victims were Latoya Smith, 22; her daughter, Remedy, who would have turned 1 today; Aaliyah Griffin, 6, who Clark said was related to Smith; and Gina Marie Rosario, 7, the daughter of a neighbor.

Officials yesterday tried to calm tensions created by early reports that Cradock crashed the silver Pontiac Grand Am because he was fleeing a high-speed police pursuit.

Mayor Nutter called the four deaths "just a completely crazy random action."

"There's not a situation in the city where there should be a feeling of any kind of panic, but we are constantly telling the public that there are people on the streets who should not be," Nutter said.

"The bottom line is unfortunately there are some bad people in society who do the craziest things that are unexplainable," he added.

"This was not a pursuit," Clark told reporters at yesterday's news conference.

Clark said a traffic patrol officer approached the Pontiac from behind as it was stopped at a traffic light on Roosevelt Boulevard at Third Street.

The Pontiac's driver apparently spotted the officer getting out of the vehicle; drove up on the pavement, sideswiping several cars in traffic; then sped south on Third Street.

"The vehicle took off. He got back in" the patrol car, Clark said. "He wasn't even in a close proximity. He could see [the Pontiac], but he was not close enough to him to consider a pursuit."

A tape of the police radio conversations seems to validate Police Commissioner Charles H. Ramsey and Clark's assessment.

There is no sense of urgency in the officers' voices, just the relaying of information - until the traffic patrol officer arrives on the scene a few minutes after the 7:36 p.m. crash.

"We got a lot of injuries down here. Get me some rescue," the patrolman says into the radio, concern in his voice.

"Let me know where the injuries are. What are the injuries?" replies the dispatcher.

"Get me some rescue . . ."

"Let me know where to send them at, sir," replies the dispatcher. "Where are they? . . ."

"Annsbury and Third Street," the officer quickly answers. "Get me rescue."

Police said the Pontiac sped down Third Street and then appeared to jump the curb just south of Annsbury.

The Pontiac ran over Smith, seated on a stoop with a baby carriage nearby and the two young girls talking to her. The girls' backs were to the car. The baby was ejected from the carriage on impact. The girls were caught under the car. The vehicle stopped when it wedged and crumpled between a house and utility pole.

Ramsey called the scene of the crash "horrific."

Police did not know how fast the car was traveling at impact, but Ramsey said it must have been moving at high speed: "There were no skid marks that I saw . . . which means there was no attempt to break the speed prior to impact."

The chain of events began at 7:29 p.m., when, police said, the two men accosted a 29-year-old motorcyclist in the 5400 block of Rising Sun Avenue in Olney.

One of the robbers drew a gun and ordered the motorcyclist to surrender his bike, which was later recovered, police said.

One of the robbers, who police allege was Rodriguez, jumped on the Yamaha and sped off toward the Boulevard. The gunman, who police allege was Cradock, got into the Pontiac and sped off after the cycle.

Moments later, police said, the traffic patrol officer was stopped by an unidentified man in an SUV, who pointed out the Pontiac at C Street and the boulevard and said it was just involved in an armed carjacking.

Ramsey said the fault for Wednesday night's events belongs solely with the two suspects: "They committed an armed robbery. They have a long list of violent offenses. They have guns. They're out harming people. They have no regard for life whatsoever."