Wayne B. Williams, a 23-year-old freelance photographer who has been the subject of intense police surveillance, was arrested today and charged with murder in one of the slayings of 28 young blacks here, officials said.

Williams, who is black, was charged in the death of Nathaniel Cater, 27, the most recent and oldest of the victims, said Atlanta Public Safety Commissioner Lee P. Brown.

The charge against Williams was the first since the string of slayings began almost two years ago, although others have been questioned and released in the cases.

Brown, who declined to say what prompted the arrest, said Fulton County District Attorney Lewis Slaton will announce later the date of a hearing for Williams.

Two plainclothes officers arrested Williams this afternoon at the northwest Atlanta home he shares with his parents, both retired schoolteachers.

Uniformed policemen kept reporters and the curious away from the tightly shuttered Williams home. The suspect's father, Homer Williams, walked from the house once but only shook his fist at reporters who asked him for comment.

Police Chief George Napper and Maj. W.J. Taylor, administrative head of the special task force investigating the chain of killings, spent 10 minutes inside the house and then emerged without making a statement.

Brown said the investigation "will continue full steam ahead. We are going to continue our investigation. We have made an arrest in one case," Brown said Officials have often said in the past that more than one person is thought to have committed the slayings.

Brown refused to commnet on any evidence authorities have gathered against Williams. But an official involved in the probe said police decided to make the arrest after completing laboratory tests on fiber evidence removed from Williams' house and car, as well as fibers found on Carter's body.

Cater was found floating in the Chattahoochee River on May 24, where the bodies of six of the 28 cases being investigated by a special police task force have been found.

The body was found two days after Williams was stopped by FBI agents and police who had staked out a bridge over the river.

Police said they heard a splash while Williams' car was on the bridge, and Williams was stopped and searched. Police place him under surveillance and questioned him on June 3 and 4.

Cater, at 5-foot-10 and 150 pounds, was the largest of the victims. Most of the other victims were teen-agers, although some of the more recent killings were of men in their 20s, most of them considered to be mentally retarded.

Williams was questioned for 12 hours on June 3 and 4. Although he was not arrested or charged, police have since kept a daily vigil outside his home.

In a news conference the day after he was questioned, Williams said the FBI had told him "You killed Nathaniel Cater" and informed him he was a "prime suspect" in some of the slayings.

At the news conference, Williams denied throwing anything off the bridge.

Investigators close to the case have said fibers found on the bodies of some victims match some fibers taken from Williams' home the night of June 3.

The arrest capped several frantic weeks of investigation by hundreds of local law enforcement officers and the FBI. Slaton said as late as Thursday that he did not believe there was enough evidence for an arrest or an indictment in any of the killings.

The FBI agents and police officers conducting the stakeout May 22 at the Chattahoochee River bridge heard a splash shortly before they stopped Williams.

He was stopped not far from the bridge while driving on Interstate 285 in a white station wagon owned by his family. FBI agents interrogated him that night but did not take him into custody, and he was placed under surveillance shortly after the incident.

FBI agents and members of the special taks force tailed Williams until they realized he was aware of the surveillance and brought him in for questioning. After he was interrogated on June 3 and 4, however, Brown announced that police had insufficient evidence to make an arrest.

Tonight, authorities declined comment on specific measures taken to ensure Williams' safety in jail, except to say he was in a secure cell. A policeman outside the Fulton County jail said, "He is lying down and resting. He seemed to be real calm."

The suspect was described by associates as a radio electronic whiz who had learned the ways of policemen through occasional work as a free-lance television cameraman.

While remembered as bright and aggressive, his friends said his attempts to gain full-time employment as a TV news photographer never bore fruit. Camerman for broadcast stations here said Williams was something of an ambulance-chaser, frequently seeking to sell film of homicides or wrecks.

"He had all kinds of police radios in his car," said one cameraman, who asked not to be identified.

Since he was first connected with the investigation, Williams has remained the focus of news media attention. Williams' attorney, Mary Welcome, has filed suit in federal court seeking an injunction prohibiting police and news organizations from linking him publicly to the slayings. U.S. District Court Judge Orinda Evans had said she would rule on the suit Tuesday.