Police issued a warrant for Wardlaw's arrest, charging him with murder and aggravated assault.
Hill told a neighbor that her son had raped her and had killed her daughter. Police weren't sure that any rape had been committed but tests were being performed.
After the attack, Hill, covered with blood and dirt from the cellar, suffering four stab wounds and a fractured left shoulder, staggered across the street and pounded on a friend's door.
"She was standing there covered with blood and dirt and she didn't have any clothes on at all," recalled Ruby Crafton.
"She fell on the floor and said, 'He raped me and he killed Melody.' Then she passed out."
By the time police arrived, Wardlaw, 22, had fled his family's house on Van Pelt Street near Cambria, where the attacks occurred shortly before 10 a.m.
Hill was admitted to Temple University Hospital in guarded condition.
Police said Wardlaw had been staying with his mother and 19-year-old sister, Theresa Wardlaw, who was called Melody, since August, when he was paroled from the State Correctional Institution at Camp Hill. He had served six years for two rapes, authorities said.
Melody Wardlaw's nude body was found in the basement when police arrived.
Hill gave police a statement in the hospital in which she described the attack in gruesome detail, a source said.
She related how she and her daughter had become terrified of Irwin, who was known as Nate, after he began to display his strange behavior. They told friends and relatives about it, and Hill had gotten her boyfriend to live with them for a time.
After Hill's boyfriend left, Melody got her boyfriend to spend Sunday night in the house. But he left to go to work yesterday morning, leaving the two women alone with Nate.
At about 9:45 a.m. yesterday, Melody's boy friend called the house to see if everything was all right, Hill told police. She said she took the call in her second-floor bedroom.
She went to look for her daughter but couldn't find either her daughter or her son. She told the boyfriend that Melody was not at home and hung up the phone.
She stepped out in the hall, she said, and Nate was standing there with a knotted bed sheet and a knife in his hands.
"I'm going to kill you," she quoted her son as saying.
"Why?" she said she asked.
"Why not?" Nate responded.
"What did I do?" the mother said she asked.
"You won't give me any money," Nate said.
"I'll give you some money," Hill said.
"I'm still going to kill you," she said her son said.
Hill said she went into the bathroom and her son followed her in and began choking her with the sheet. She said she passed out and the next thing she knew, she was in the basement, nude.
She said she assumed her son had taken off her clothes, stabbed her and dragged her down the stairs, pulling on her left arm because that shoulder was broken.
Hill said she saw that her daughter was lying in a pool of blood on the cellar floor, stabbed numerous times in the back. Hill said she pretended to be unconscious. Her son picked up her daughter's body and threw it on top of her, Hill said.
She said she remained still and Nate went back up the stairs.
Police said the suspect cleaned the house thoroughly before he left. Detectives said they found a knife in the house fitting the mother's description, but weren't sure it was the murder weapon because it had been wiped clean.
The incident stunned neighbors.
"I couldn't believe he would do something like that to his mother and his sister," said Crafton, who said she has been a friend of the family for 15 years. "He had problems but I didn't know they went that deep."
The night before the attack, police said, Melody called another sister, Kim, who lives nearby, and told her of her brother's bizarre behavior.
Crafton said Hill called her about 9 a.m. yesterday to say that her son had stolen a guitar from the house and had taken it to a pawn shop. She said Hill wanted to borrow $55 to reclaim the guitar, which belonged to a friend.
Crafton was unsure whether the guitar led to yesterday's violence. But she said Hill told her that her son was following her around the house that morning, and that whenever she entered a room and switched on a light, he switched it off.
"She finally locked herself in her room so he couldn't get in," Crafton said. According to Crafton, Hill "was always a little afraid" of her son.
Hill said her son occasionally threatened her, "but she would never think anything of it because he was her child," Crafton said.
Hill, who worked as a housekeeper at Episcopal Hospital, recently got her son a job at the hospital's snack bar, according to Crafton.
Nate Wardlaw, convicted in 1980 of rape and attempted rape, was sentenced to 5 to 15 years in prison.
According to a spokesman for the Board of Probation and Parole, Wardlaw was turned down the first time he sought parole, in December 1985. In denying the request, the board cited Wardlaw's need for "sex counseling" and for drug and alcohol treatment.
Also cited was the violent nature of the previous attacks and the fact that knives had been used.
The board granted Wardlaw parole in September, though it ordered him to undergo sex counseling and outpatient drug-and-alcohol therapy. The board also ordered Wardlaw not to associate with the victim.
Joseph Crafton, 18, who grew up with Wardlaw, said that no one was sure what to think about Wardlaw after he returned from prison.
"When he got out he seemed OK," said Crafton. "He was full of smiles." On the other hand, he said, Wardlaw never acted sorry for his crimes and didn't seem to treat them seriously.
"He was very casual about the whole thing," said Crafton. "I was scared to talk to him about it. I think everyone else was too."
"Whatever he did, he was never sorry for it," said Chris Jennings, 48, another neighbor. "What happened today was a terrible shock, but I wasn't surprised he would do it again."
According to Joseph Crafton, Wardlaw was a quiet teen-ager who never got into trouble and often stayed at home. As a result, he was picked on by the neighborhood "tough guys."
"He was the nice kid on the block," Crafton said.
About a year before he was sent to prison, Wardlaw changed, Crafton said. He began hanging out on street corners with other youths, and he traded his ''preppy clothes" for more stylish clothes and gold chains, he said.
According to police, he hung out with a gang in the area of 20th and Somerset streets, and had the nickname "Macaroni." Police said Wardlaw had a
criminal record as a juvenile, and when he was 16 was sent to a Montgomery County reformatory. His juvenile record was unavailable.
Neighbors said Melody Wardlaw graduated from Gratz High School in 1984 and attended Temple University for a short time. She had decided to enlist in the armed forces and was trying to lose the necessary weight, they said.
Joseph Crafton said she had been working at a Center City McDonald's restaurant.