The man accused of infecting at least 10 young women with the virus that causes AIDS kept score of his sexual acts and later recalled dozens of the names of women with whom he had sex.
Indeed, Nushawn Williams' fascination with record-keeping helped in the painstaking task of tracking down the women and building a case against him, authorities said.
"He was a scorekeeper and a very, very good historian," Dr. Robert Berke, Chautauqua County health commissioner, said Tuesday.
Williams had sex with the women -- one as young as 13 -- and made many other sexual contacts even after he knew he was infected and had been warned of the risks, officials said. They described him as a sexual predator who lurked around schools or parks in Chautauqua County, befriending young women and often exchanging drugs for sex.
"It takes an individual with no regard for human life to do something like this," said Chautauqua County District Attorney James P. Subjack.
Authorities are now looking into the possibility that he infected women elsewhere in the state.
Williams, who will be 21 Saturday, gave Chautauqua County health officials the names of 28 sexual partners in September 1996, when he was diagnosed with HIV.
A few days ago, he offered to officials in New York City the names of 50 to 75 sex partners. It is not yet clear whether they include the 28 sex partners from Chautauqua County.
"He seemed to take some delight in keeping records," Berke said. "And he obviously has a very, very good memory."
Williams, who lived in the county for about a year beginning in mid-1996, was arrested Sept. 22 in New York City and is being held in jail there on charges of attempted robbery, possession of a controlled substance and resisting arrest. He was arrested in the Bronx on charges of selling $20 worth of crack cocaine to an undercover detective.
Investigators spent months tracking down his known 28 sexual partners in Western New York, as well as other sexual partners they may have had.
Health and law enforcement officials' concerns grew as they turned up far more cases of HIV infection than the semirural county normally gets.
The county has had only about 50 AIDS cases since the epidemic began in the early 1980s.
Suddenly health officials were faced with 10 HIV-infected women in a short period of time.
"You have to know that something is very wrong," Chautauqua County Executive Andrew Goodell said.
Establishing the link between Williams and his sexual partners was made even more difficult by his use of aliases, including Face Williams, Headteck Williams and "E" Shyteek Johnson.
"It wasn't the same name -- only much later did we learn Williams used several aliases -- but it was the description they would give of the sex partner and certain other characteristics that led us to believe we were talking about one person," Berke said.
New York confidentiality laws prevent people who are HIV-positive from being identified. But Williams' identity was released Monday after prosecutors persuaded a judge in Mayville that Williams' threat to the community was more important than the protection of his privacy rights.
The decision by Supreme Court Justice Joseph Gerace was the first such waiver of privacy rights in the state.
Although Williams became a prime suspect, Berke said investigators could not tell any of the sexual partners that Williams was HIV-positive.
"It was frustrating," said Chautauqua County Sheriff Joseph Gerace, the son of the judge. "When you have an investigation, you have the name of the victim and the suspect. We had neither."
So far, authorities know that at least one man was infected with HIV through sex with one of Williams' known area sex partners. Berke said as many as 70 more people in the county may have been exposed to HIV that way.
Authorities are continuing their investigation of those sexual contacts. Health officials have said Williams also traveled between New York City and the Southern Tier and may have had sexual contacts in other counties.
Route 17 is considered a pipeline from New York City to Western New York for drugs and drug dealers.
"Williams is one of many," said Capt. Randy Present, Jamestown's chief of detectives.
"We're considered easy pickings," he said. "We're a ready, open market, especially for people who want to sell drugs without worrying about getting their brains shot out by the competition."
One of Williams' sexual partners, who was infected, traveled to Rochester and had sex with four people, said Dr. Barbara DeBuono, the state health commissioner. But none of them appears to be infected.
It was only in recent days that one of Williams' sexual partners -- the 13-year-old, now 14 -- agreed to talk to law enforcement officers about her experience.
"Finally, we learned the name of someone we had been investigating for weeks," Gerace said.
Her statement led Subjack to file rape charges against Williams.
Berke said that since Williams' name and photograph were released, there has been a flurry of phone calls to his department. The information could lead to reports of additional sexual contacts and more charges against Williams.
Authorities said they intend to pursue charges of reckless endangerment and first-degree assault against Williams for each person he allegedly infected. The state does not have a law that specifically addresses knowingly or intentionally infecting someone with HIV.
"As victims finally agree to talk to us, we will bring individual charges against Williams for each one," said Gerace. "Our job is just beginning."
In Albany, Gov. Pataki said he believes Williams violated felony laws and should "never see the light of day again."
He said the question of who will prosecute the case -- Subjack or state Attorney General Dennis C. Vacco -- remains unanswered. Pataki said if any district attorneys ask for a special prosecutor to handle the case, he will appoint Vacco.
Williams' youngest sexual partner was treated by Dr. Neal Rzepkowski, an HIV-positive physician in charge of the county Health Department's clinics for patients infected with the AIDS virus.
He said Tuesday that the girl went through depression and considered suicide.
"Everybody who tests positive thinks they are going to die right away," he said. "But she is beginning to believe that with the proper treatment and care, she can look forward to a good future."
Rzepkowski said he is also treating three other women who allegedly contracted the HIV virus from Williams.
"One of them -- she's 19 years old -- is pregnant but doesn't know if Williams is the father," he said.
Rzepkowski said not all the women traded sex for drugs, nor were they all poor.
"They represent the gamut -- mostly from lower- to middle-class families," he said.
Staff reporters Tom Precious and Henry L. Davis assisted in this story.