It was just after midnight and the grownups were still seated around the dinner table at Jerry Wilder's Southeast Washington home, friends and family leisurely digesting Friday night's fish fry and chatting about growing old. Then they heard a popping sound from the back bedroom, where the children had been sent to watch television.

At first, Sandra Johnson thought it was a balloon. But then she bolted from the dinner table, saying to herself, "There ain't no balloons in the house."

Her mother Mary Lee thought someone had broken a window, and rushed to the bedroom. Lee stepped into the doorway and gasped.

Frederick Wilder, a curious and wide-eyed 4-year-old, had just placed his father's .38 caliber revolver on the bed, next to Frederick's 9-year-old cousin, Derrick T. Johnson, who lay stretched out on his back, eyes half open, blood streaming from the corner of his mouth, his feet dangling off the side of the bed. Derrick had been shot in the head.

"Fred shot Derrick," said 9-year-old Jerry Wilder Jr., one of children who had been watching television.

Derrick Johnson was pronounced dead on arrival at Greater Southeast Community Hospital less than an hour later, becoming the second young child shot to death this year in Washington, a city with one of the toughest handgun control laws in the country.

On Feb. 2, Marquis Copeland, 6, was shot in the head while lying in bed after two men who hed left a party at his parents' home on Florida Avenue NE returned around 3:30 a.m. and started shooting.

The gun that killed Derrick Johnson early yesterday morning was not registered as required by law. Frederick's father, a 28-year-old guitar player formerly with Chuck Brown and the Soul Searchers band, had obtained it mainly for his wife's protection when he worked late. Wilder has been charged with possession of an unregistered firearm, which carries a penalty of up to a year in jail.

In this section of Southeast Washington, the Savannah Terrace Housing Project just off of Alabama Avenue near the Suitland Parkway, guns are considered by many to be a necessity.

Wilder usually kept the gun in the breadbox on top of the refrigerator, Lee said yesterday, as she and nearly a dozen friends and neighbors sat in the living room of her modest two-story town house several blocks from where Derrick was shot.

With childrlen coming over for dinner that night and elderly women scurrying about the kitchen, Wilder decided to move the gun to what he considered a safer spot. He put the gun under his pillow in the back bedroom, where the children were sent to watch television.

The 4-year-old boy appeared stunned after the shooting and sat silently on a relative's lap as Derrick was carried to a waiting ambulance. During questioning by police, the boy remained calm as he explained how he had discovered the gun under the pillow, cocked the hammer and fired it. When asked if he had ever seen the gun before, the boy reportedly told police, "Yeah, I took it outside." According to witnesses, the questioning officer was stunned at this. "I don't believe it," he replied.

"I don't know what trauma he's going to have later on because of this," said Barbara Brawner, Derrick's great aunt. "He is so young, I think God will let him forget."

Cynthia Wilder, the boy's mother, became hysterical after the shooting, collapsed three times and was briefly hospitalized for shock. Friends said she was apprehensive about returning to her home. Neighbors described Jerry Wilder as "very upset."

"He don't do no talking -- he feels so guilty," said Mrs. Lee, the slain boy's grandmother. "I say we don't hold that against him, but he still can't sit down. He just keeps on moving."

Derrick was described by those who knew him as an above-average 9-year-old, a third grader at the Garfield Elementary School with a profound enthusiasm for sports, especially football. Independent and sensitive, he was known to contend, "You talk like I'm a baby. I'm a big boy now."

"He was kinda nice," said a sad Cathleen Jones, an 8-year-old classmate who lived in the same apartment complex. "My mother heard the shot but she thought she was dreaming. Then I heard people start to cry."

In this rough-and-tumble-looking neighborhood, where red ribbons adorn the antennas of many cars to protest the slaying of black youths in Atlanta, many youngsters have a hardened look that belies their years.

"When something like this happens all you can say is it must have been his time," said a reflective Eric Karim, Derrick's 12-year-old next-door neighbor. "God put him in that position, just called him on up."

Back at the Lee home, talk turned to the handgun, an issue on which there was no clear consensus.

"I'm not for violence. I don't think there should be guns in a house where there are children," said Mrs. R. B. Singletary, a friend of the family.

"If everybody was disarmed, that would be one thing," countered her husband, a former security guard at L'Enfant Plaza and a member of the National Rifle Association. "But some people only have in mind disarming the Negro -- and not the KKK. Look right here in Washington. All this gun law.Then you have Charlie coming in from Maryland and Virginia with rifles on the racks."

"It's just the way this society is," said another visitor. "With television the way it is, you put a doll and a gun in front of a child and the kid will go for the gun."

"Seeing as how we are stuck with the gun, it seems that we could be more careful," Singletary said.

The house was silent then except for someone crying in the kitchen.