BUFFALO, N.Y. -- The author of a New York Times bestseller is now writing a book about Western New York's infamous .22-caliber killer, who started his murder spree 36 years ago this month.

Catherine Pelonero was a child when Joseph Christopher committed his killings, so she can't remember much. However, she's spent the past year researching the case.

"I thought, this story is stunning," Pelonero said. "I've got to write this book."

The exact death toll from Christopher's attacks is unknown; however, he's admitted to more than a dozen killings between 1980 and 1981. The first four happened within a 36-hour period. Christopher killed 4 black men in Buffalo, Cheektowaga and Niagara Falls. He used the same .22-caliber gun in each.

"Very quickly, the police connected that it was the same shooter," Pelonero said. "It all came from the same .22-caliber weapon."

Christopher was also responsible for a series of stabbings in New York City, Rochester and Buffalo, and he was suspected in the brutal beatings of two Buffalo cab drivers, although Pelonero isn't sure he actually committed those crimes.

In 1993, Christopher died in prison at the young age of 37 from a rare form of male breast cancer.

Pelonero said she was shocked at the lack of in-depth accounts of Christopher's killings. A big focus of her book will also be on mental illness.

"Was he sane enough to have gone through this trial," 2 On Your Side's Michael Wooten asked Pelonero.

"No. No he was not competent to stand trial," she responded.

Pelonero said she will also devote a chunk of the book to the victims, who are often overlooked in the histories of serial killers.

"That's one of the best things I can do as an author," she said.

Pelonero, who previously wrote the New York Times bestseller 'Kitty Genovese: A True Account of Public Murder and Its Private Consequences', has wrapped up the research phase of the new book.

She expects the .22-caliber killer story -- tentatively titled 'Absolute Madness' -- will have a hardcover release in the Fall of 2017.