Michael Cameron McIntosh, a thin, 23-year-old black man who weighed perhaps 100 pounds and looked like a child, today became the 25th victim on the swelling list of murdered black youths under investigation by Atlanta's special police task force.

His naked, decomposed body was pulled from the Chattahoochee River last night, one day after the body of 15-year-old Joseph (Jo Jo) Bell -- the 24th casualty of an elusive killer or killers who have terrorized this southern city for city for nearly two years -- was discovered in another river.

Atlanta Public Safety Commissioner Lee Brown said the McIntosh case was assigned to the task force today because of "similarities in his profile and that of the other cases."

"When you look at where the body was found, the cause of death, the area of town where he came from -- these factors lead you to believe there's got to be some kind of connection," said Fulton County Police Chief Clinton Chafin in an interview.

For one thing, medical examiner ruled today that McIntosh died from asphyxiation, making him the 14th victim in the gruesome string of slayings of young blacks to die from either asphyxiation or strangulation. His death was turned over to the task force within hours of the autopsy.

For another, he was the sixth victim to have been found unclothed. Five others have been found wearing only undershorts.

When he was not drifting, drinking and hunting odd jobs, McIntosh sometimes lived with his aunt in a yellow frame house with a tarpaper roof in an impoverished, rat-infested inner city neighborhood several blocks from the housing project where Yusuf Bell, 9, the fourth victim, disappeared. He was also friendly with Jo Jo Bell (no relation to Yusuf), who worked part-time sweeping up at Cap'n Pegs Seafood Carryout on block from McIntosh's house, said Marvita Patrick, a clerk.

Police retrieved McIntosh's body from the Chattachoochee River in remote southwest Fulton County within miles of the site where two other victims were pulled from the river one day apart in March. He is the sixth victim to have been found in an area river.

McIntosh also falls into the category of two other adult victims, Eddie Duncan, and Larry Rogers, both mentally retarded young men who, say friends, appear to have been trusting of strangers and more vulnerable than many of the streetwise children who have become victims. While not retarded, McIntosh appeared "slow in the mind" when he drank, says a childhood friend, Tony Dubose, 23.And McIntosh, who had a criminal record for burglary, aggravated assault and parole violations and was often picked on by bigger "dudes," says one friend, drank a lot.

"The last time I saw him, about a month ago at Cap'n Pegs, he was bombed out," said Dubose, an unemployed laborer. "He was boasting about getting himself back together. He asked me if I knew about any jobs, but I couldn't tell him nothin" because I wasn't working." He told friends he had enrolled in a CETA training program to become a welder.

He often stopped by West Quick Shop, a red cinder block corner market across the street from the fire-damaged home his grandmother left him when she died last year, to ask about work. "He said he'd mop floors, do anything," said owner Connie Taylor, who declined his offer. "I told him if he could straighten himself up and stop drinking, I'd give him a job. He was quiet, a loner and he was depressed because he couldn't get a job."

No one has seen him in the neighborhood for about a month, say police. He often disappeared for weeks, only to turn up and brag that he had been "out of town working," said Dubose.

Since the three recent victims have been under-sized adults, some authorities have apeculated that the city-wide curfew and parental concern may be depriving the killer or killers of accessible children, leading him to prey upon helpless or unwriting adults who appear to be child-like.