The number of missing and dead children grew to 21 today as police determined that the death of a youth whose body was pulled from the Chattahoochee River in December was part of the pattern of child killings here and ought to be investigated by a special task force.

The latest victim was Patrick Rogers, 16, once a streetwise youngster, like so many of the other black youths who have been murdered in the last 19 months. All but two of the victims have been male, and all were between 7 and 15.

Rogers' was the third case turned over to the task force in the last week.

Rogers' age and profile fit those of many of the missing and murdered children. Like several others, he hustled for spare change outside neighborhood grocery stores. But Atlanta Public Safety Commissioner Lee P. Brown had insisted, until today, that there was no connection with the other cases.

He gave no reason why he had changed his mind. Officials in Cobb County, where Rogers' body was taken from a cable in the river, across town from his stamping grounds, have said repeatedly that the rogers case should be investigated.

"We don't have any evidence to say he is one of those [children murdered], but he did live in the right area on the south side of Atlanta, and he is the right age," said Cobb Police Capt. Penn Jones.

Initially, Jones said investigators did not believe that Rogers' death was related to the black children found murdered. They searched for a month before finding his body, and speculated that he was hiding out to avoid a burglary warrant. Friends say Rogers didn't know about the warrant.

Finally, investigators concluded that Rogers' death "could be connected," said Jones, after they found nothing to suggest that any of his friends, acquaintances or relatives played a role in his death.

Moreover, Rogers lived less than a quarter-mile from a grocery store where Aaron Wyche, another victim, was last seen, and near the spot where the body of another child, Aaron Jackson Jr., 9, was found.

The medical examiner, Dr. Joseph Burton, never determined the cause of death. The body was too composed. But a blow to the head was believed to be the primary injury. Nine of the victims was strangled or asphyxiated.

Meanwhile, police said two black children reported missing earlier this week have been found safe and have been returned to their parents.

Scare stories about the two disappearances were cited by police as evidence of tendency by the news media to overreact to the 227 children reported missing since Jan. 1, a number inflated by anxious parents who are quick to "panic if their child is three minutes late getting home" and call authorities, one officer said.

Two of those reported missing this year -- Lubie Geter, 14, and Patrick Baltazar, 11 -- have been found murdered. They are on the task force list.

Twelve other children under 17 who have been missing since Jan. 1 remain unaccounted for, but only one, Curtis Walker, is under investigation by the task. Eight others are girls, suspected of having left home to live with their boyfriends.

Of the three others, only one is black, a 15-year-old with a history as a runaway. Police say he has been spotted several times since he left home Feb. 20.