Freed Rape Suspect Arrested Again in Another Case : Crime: Canoga Park woman attacked in her home. Officials say they lacked evidence to prosecute man in an earlier sexual assault.

A man released from jail on rape charges Tuesday was arrested on suspicion of raping a Canoga Park woman in her home before dawn Friday after a 9-year-old neighbor boy, awakened by her screams, persuaded his drowsy father to phone police, investigators said.

Stephen Arnold, 31, was caught about 12:45 a.m. climbing through a first-floor bedroom after raping a 20-year-old woman in front of two roommates, Los Angeles Police Detective Bob Hart said. He had been arrested July 5 for an alleged rape, also in Canoga Park, but was released after prosecutors decided they lacked evidence to file charges, Hart said.

In that case, the woman’s story could not be corroborated and her reliability was tarnished by a “lengthy prostitution record,” said Deputy Dist. Atty. James Baker.

“It was just entirely a credibility problem,” Baker said.

On Friday, Arnold returned to the Van Nuys Jail, where he was being held in lieu of $110,000 bail on the latest rape arrest. Arnold moved to Canoga Park about a month ago from Brooklyn, N.Y., said Hart. He said he expects the case will be presented to the district attorney’s office Monday.

The detective credited a young boy with the arrest, because his father’s phone call enabled police to arrive at the two-story apartment building before the suspect escaped. The child, who had learned in school about dialing 911 in emergencies, woke his father, Hart said.

“I said, ‘Dad, a girl’s screaming. Dad, a girl’s screaming,’ ” the boy recalled later. His father asked that the child’s name be withheld.

The father was sleepy and did not immediately grasp the urgency of the boy’s message, father and son said.

“I told him to call the police cause that girl was screaming,” the boy said. After police arrived, the tearful woman came over to thank him, he said.

Hart said Arnold knocked on the door of the victims’ apartment, in the 7000 block of Jordan Avenue, saying he had car trouble and offered them $10 to use their telephone to call for help. He said they were wary because of Arnold’s shabby dress and the late hour, and claimed that they didn’t have a phone.

“Then he pushed the door open with bodily force and pointed what they thought was a shotgun at them, but it turned out to be pellet gun,” Hart said.

Arnold made three of the apartment’s four tenants lie on the floor--the fourth remained asleep in a bedroom--and demanded money from all of them, Hart said. Then he raped the woman in front of her two male roommates, who still believed Arnold was armed with a shotgun, Hart said.

When police arrived at the apartment, Arnold said without opening the door, “Everything is all right, officer,” Hart said.

But the patrol officers remained suspicious because they heard what sounded like moaning. They kicked in the door and Arnold tried to escape through a bedroom window, waking the fourth tenant as he fled, Hart said.

“As he came out of the window, he was greeted by two police officers” who had been called as backup, Hart said.