Steven Amos, 17, Richard's brother, was treated for bullet wounds and was listed in serious condition last night at Cooper, where he was under police guard, according to a hospital spokeswoman.
Camden County Prosecutor Samuel Asbell said indications were that the 17- year-old had stabbed Brey. Asbell did not identify Steven Amos, but a police source did.
Pennsauken Township Committeeman William Orth said Brey had answered a radio call in his police car at 4:45 p.m., sending him on a complaint about a ''loud party" at a house in the 1900 block of 46th Street.
The Amos youths lived at the house, which is located in a working-class neighborhood of two-story brick homes about five blocks from the Camden border.
Asbell said Brey was stabbed in the chest three times after he knocked on the door of the house. "There are reports that there was a beer party at the house," Asbell said.
A police source said late last night that officers searching the house found a stiletto-type knife that they believed was used to stab Brey.
Brey was believed to be the first Pennsauken police officer killed in the line of duty.
Asbell said Richard Amos was found in Yost Park, about a block from where he was shot.
Witnesses said Steven Amos ran from the area, but returned about 10 minutes after the shooting in a car driven by his mother and was then taken to the hospital by police. The youth, wearing jeans and a yellow tank top, was bleeding profusely from his side, witnesses said.
Police took a 16-year-old boy into custody after he surrendered to them shortly after the incident. Asbell said police questioned the youth and released him without any charges. He said the 16-year-old was at the party but was not involved in the scuffle with Brey.
Asbell said the 16-year-old apparently panicked after the incident and fled.
Ken Sweeten, an attendant at the Family Mobil Station, 46th Street and Westfield Avenue, said he heard several shots, ran from a service bay to the street and saw Brey writhing in pain on the ground in front of the house.
Sweeten said that about 10 minutes before he heard the shots, he heard Brey speaking over his patrol-car loudspeaker to two teenage boys who were running across the roofs of homes in the 1900 block of 46th Street.
"You guys get down off that roof," Sweeten quoted Brey as saying over the speaker.
A neighbor of the Amos family, who did not want his name used, said the family had lived on 46th Street for six or seven years.
"The officer came to the door, asked if I had a complaint," the neighbor said. "I said I'd check with my wife. The next thing I know I heard a commotion, like someone being slammed against the wall."
The neighbor said he then left his home and looked into the Amos home through the open front door. "All three had him surrounded like he was hogtied," the neighbor said. He said he went back to his home to call for more police and then heard gunshots.
"The officer came out, collapsed on the lawn," the neighbor said. "My daughter gave him first aid. She did what she could. She cleaned the wounds off and tried to stop the bleeding."
He said that the Amos boys' father did not live with them and that there had been problems in the past with the boys' running on neighbors' roofs. He said the roofs are accessible through skylights.
Another neighbor, Stephen Hubbs, 19, said he was walking down the street when he saw a police car pull up to a house.
"These three kids were on the roof having a party up there," said Hubbs.
When the lone officer in the car walked into the house, he was attacked by one of the youths, said Hubbs.
"As the cop was going down, he shot him (the assailant) and hit him twice in the chest," Hubbs said.
The officer then staggered from the door as other officers began arriving, Hubbs said, adding, "It happened so quick."
Immediately after the shooting, Steven Amos ran past the service station where Sweeten worked. Gene Farley, owner of the station, said he recognized the youth from the neighborhood.
"I've been here for five years and I've known him since he was that high," Farely said, extending his hand at his waist. "He comes in here all the time to buy sodas."
Pennsauken Patrolman Eric Davies said he last saw Brey when they came on duty at 4 p.m. yesterday.
"It's like losing a member of your family," Davies said. "He was level- headed. He kept his wits about him."
A neighbor of Brey's, who declined to be identified, said she had watched Brey grow up. "He was a very nice boy. . . . I liked him very much," the neighbor said. "He was just a normal boy. He made a fine policeman."
Detective Sgt. George Morris, a 31-year veteran of the force, said Brey was believed to be the first Pennsauken police officer killed while on duty.
Morris said the police station flag has been at half-staff all week, honoring slain police officers as part of the observance of National Police Week.
Robert W. Singer, the township's director of public safety, said that a memorial service for slain officers was scheduled for noon today at Cooper River Park and that it would proceed as scheduled.
Brey, who was married, had been on the force for 10 years.
Deputy Chief David Undercuffler said Brey graduated from Woodrow Wilson High School in Camden and received basic and advanced police training. Undercuffler called him "an excellent police officer."
Officials said it was routine for officers to be on patrol alone. The Pennsauken Police Department has 86 members.
After the incident, about 100 people milled about on the street, and directly across from the house where the incident occurred, several women held each other and sobbed.
There were splashes of blood on the sidewalk in front of the home. The dead officer's car was parked with its windows rolled down, and his night stick, his hat and a pack of cigarettes were on the front passenger seat.
"In this neighborhood, things are getting pretty bad," Hubbs said.