New Book Reveals Joe DiMaggio's Torment After Marilyn Monroe's Death And He Knew Who Killed Her 

Marilyn Monroe and Joe celebrating at Chasen\'s after she left her handprints in cement at Grauman\'s Chinese Theatre, 1953. 

Joe DiMaggio‘s love for actress Marilyn Monroe is well catalogued, but a new biography written by one of the Yankee great’s longtime friends delves deeper into their fabled romance — revealing what qualities he loved most about her, why they divorced, and whom he blamed for her death.

“Joe was very honored and privileged to have Marilyn Monroe as his wife, which is why he was so fiercely protective of her,” says Dr. Rock Positano in an exclusive interview with PEOPLE about

Dinner with DiMaggio: Memories of an American Hero,

with brother John Positano. “He felt that she was very vulnerable and very sweet and that it was very easy for people to take advantage of her.”

In the book released Tuesday, Dr. Positano recounts what he learned over the course of his ten-year friendship with the centerfielder who was 40 years his senior. They met after Positano helped DiMaggio with an old heel spur injury, and most of their deep conversations occurred in restaurants throughout New York City.

In one of their more intimate chats, Positano learned that DiMaggio loved his sexual connection with Monroe. Both divorcees, Monroe and DiMaggio married in 1954, but split just nine months later.

” ‘When we got together in the bedroom, it was like the gods were fighting; there were thunderclouds and lightning above us,’ ” Positano says DiMaggio told him.

But he loved Monroe for more than her body: “He thought [Monroe] was highly intelligent.”

In the book, he paints a portrait of DiMaggio (who died in 1999) as a multi-talented, whip-smart “Renaissance man,” who was drawn to Monroe for her talent. “He had an unbelievable eye for movies … He had a tremendous amount of respect for Marilyn because she was a really great actress.”

One of the few pictures of Joe and [Rock] together. [They] were both fiercely private and protective of one another.

While Monroe’s vulnerability ultimately entranced DiMaggio, Positano says she was drawn to his caring personality.

“The love he had with Marilyn — he was this gentleman [type],” he says. “That’s why American women would be in love with Joe DiMaggio today. He had a nurturing, caring way about him.”

Despite their connection, not everyone approved of their relationship. In 

Positano writes about the time Archbishop Fulton Sheen (the first “televangelical leader”) called DiMaggio into his office.

The Archbishop allegedly told DiMaggio that he should never have married Monroe, explaining “this isn’t the type of woman who gives people moral values.”

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“‘No one is going to tell me who to love and who to marry,\'” DiMaggio allegedly responded, and stormed out of the office.

While he repeatedly defended his short marriage to Monroe, the book reveals that DiMaggio did have some issues with the iconic star. For one, he complained that she “wouldn’t take a bath for days.”

However, the book reveals that DiMaggio’s main issue with his wife was Monroe’s inability to bear his children.

“From Joe’s point of view, they didn’t stay married because Marilyn was not able to have children. It was as simple as that. It was not about the published reports of jealousy and not wanting to take a back seat to her fame,” writes Positano. “Joe wanted kids with Marilyn, and Marilyn wanted to reward him with a family. In Italian terms, sex meant kids. Great sex meant great kids. Marilyn gave goddess sex, but no kids.” (Monroe, meanwhile, cited “mental cruelty” as the reason for the split.)

DiMaggio was estranged from his only child, Joe Jr., from his first marriage to actress Dorothy Arnold.  According to Positano, that didn’t stop DiMaggio from loving his son and the idea of family.

Baby Joe DiMaggio III holds a mini bat as his parents look on in their New York City home in December 1941

Although Monroe went on to wed playwright Arthur Miller, she returned to seek affection from DiMaggio after that union ended in divorce in 1961. Although The Yankee Clipper’s pride seemingly held him back from rekindling their romance, he continued to care for Monroe — so much so that his friendship with Frank Sinatra was ruined after the singer introduced Monroe to the Kennedy family.

Monroe struggled with drugs and depression. Her death, on Aug. 5, 1962, was ruled a “probable suicide,” but many have questioned the circumstances surrounding her death and her rumored affairs with Jack and Bobby Kennedy. Whatever her relationship was with them, DiMaggio blamed Sinatra for introducing her into the Kennedy circle.

“‘The whole lot of Kennedys were lady-killers,\'” DiMaggio said to Positano, according to the book, ‘”and they always got away with it. They’ll be getting away with it a hundred years from now.\'”

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The baseball star added, ‘”I always knew who killed her, but I didn’t want to start a revolution in this country. She told me someone would do her in, but I kept quiet.’ ”

“The understanding was that her involvement with Mr. Sinatra and the Kennedy clan put her in a position where maybe it wasn’t good for her mental health or her emotional health,” Positano says. “He didn’t think they were good people for her to be around.”

DiMaggio allegedly said at one of their dinners that “they did in my poor Marilyn. She didn’t know what hit her.’ ”

Unfortunately, DiMaggio’s fierce protectiveness and love for Monroe weren’t enough to save her.

“‘I’ll go to the grave regretting and blaming myself for what happened to her,\'” DiMaggio told Positano, per the book. “Sinatra told me later that ‘Marilyn loved me anyway, to the end.’ “

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