Officially, he did not write an authorized biography of Minneapolis’ most legendary and mythologized rock band. Bob Mehr got pretty close to an unofficial thumbs up from singer/guitarist Paul Westerberg, though, about halfway through the interview process of his new book, “Trouble Boys: The True Story of the Replacements.”

It came in the form of a tooth.

“We had been comparing dental woes one day, because he had just gotten a childhood molar removed,” Mehr recalled. “I had also asked him if he had any teenage photos of himself.

“When I got home, there was a funny-shaped envelope waiting for me: ‘I don’t have any photos, but how about my 12-year-old molar? Will that work?”

The fact that Westerberg even participated in Mehr’s book — which hits stores this week from Da Capo Press — is a clue to fans it’s a particularly biting account of the Replacements story. The notoriously hermetic and mistrustful rocker has done only a handful of interviews over the past decade, even after he re-emerged for a 2013-15 reunion run with bassist Tommy Stinson that helped the Replacements land a Rock and Roll Hall of Fame nomination and underscored the band’s enduring legacy.

More relevant than Westerberg’s contributions, “Trouble Boys” also digs deep into the life of the band’s most troubled member, Bob Stinson. Mehr pored over court documents in Minneapolis and talked with Tommy (Bob’s younger brother) and other family members about the band’s co-founding guitarist, who was fired from the group in 1986 and died in 1995.

Fans looking for amusing anecdotes about Bob’s notoriously erratic behavior will get plenty of that later in the book. Such as when he wore a unitard that ripped up the backside during an epically tumultuous “Saturday Night Live” appearance.

First, though, readers will find themselves learning about the physical and sexual abuse Bob suffered as a child in the book’s opening chapter. Later sections detail the psychological struggles and addictions he faced as an adult.

“To me, Bob’s role in this really is the heart of both the triumph and the tragedy of the Replacements,” said Mehr, who will be back in town to host a book party at the Turf Club in St. Paul on the afternoon of March 5.

“The fact that Bob was able to overcome the trauma of his childhood and reconnect with the world again through music really may be the foundation of the band.”

‘If Paul agrees to it’

Now a music critic at the Commercial Appeal newspaper in Memphis — a city where the Replacements had several ties — Mehr is also a Mojo and Spin contributor who wrote several magazine articles on the group over the years. In 2008, he was recruited to pen liner notes for a reissue of the 1985 album “Tim.” Shortly thereafter, he pitched the idea for the book.

Mehr said the key to getting Westerberg and Tommy Stinson to participate “may have simply come down to asking at the right time.”

“I think enough time had passed between the end of the band and Bob Stinson’s passing to where Paul and Tommy were finally prepared to look back in a meaningful way,” the author said, laughingly recounting that Tommy said he’d do it “if Paul agrees to do it.”

“I think that was Tommy’s polite way of getting out of it, because he probably assumed Paul would never do it.”

Mehr added, “I also feel like they wanted to understand and cultivate their legacy a little better. Other people had made attempts to tell their story — and all those projects had merit in their own way — but there hadn’t been anything the band had really been involved in themselves.”

The band’s only other living original member, drummer Chris Mars, declined to take part in Mehr’s book but is quoted from prior interviews. Two other key interview subjects talked to Mehr at length: Peter Jesperson, the band’s original manager and Twin/Tone Records co-founder, and Bob “Slim” Dunlap, the guitarist who replaced Bob Stinson in the band. Mehr met with Dunlap before he suffered an incapacitating stroke in 2012.

Jesperson and Slim’s wife, Chrissie Dunlap, applauded the book but were quick to stress that it was often not a fun read.

“Some of it’s hard to read for various reasons,” said Jesperson, whose firing by the band is also covered in depth. “But I think, for the most part, it’s an accurate and truthful book.”

In an unpretentious style befitting the band, “Trouble Boys” offers a workmanlike approach to telling the Replacements’ story.

Mehr refrained from overwriting the dramatic element. He lets the overlying themes of the band’s story surface on their own, where ample amounts of mental illness, chemical dependency, insecurity, self-defeatism and highly guarded egotism combined to make a group that a sizable chunk of musicheads think is one of rock’s greatest bands ever. He explores the human elements as much as the musical elements to define the Replacements’ chemistry.

“There wasn’t much separation between who they were and what they were,” the author summarized. “To learn more about the five or six personal stories in the band really gave me a greater appreciation of the music and the things they did accomplish. They overcame a lot of limitations.”

Guided by Paul

Beyond the group’s inner circle, the book includes interviews with dozens of industry figures who witnessed the Replacements’ clumsy jump from the underground to Sire/Warner Bros. Records in 1985. Mehr also made multiple visits to the Twin Cities to talk with dozens more people who saw the group’s rise and untold number of falls.

“I had been to Minneapolis many times before,” he said, “but it still felt very important to come back and learn the sidewalks and corners they walked, to drink at the CC Club and hang around Uptown or even go down to Paul’s high school,” Holy Angels in Richfield.

Westerberg even offered Mehr a personal “narrated driving tour” of the sites one day — with Mehr at the wheel, of course. (The rocker doesn’t drive.) Despite that, the author still did not know if he had the bandleader’s trust.

The ultimate test came just as the book was headed to the printer, when Westerberg surprised Mehr with a late request to see the final product.

“I honestly didn’t expect him to read it,” he said. “There were a few phone calls and exchanges over a long and — for me — intense weekend in December.

“I think a lot of that was to be expected: A FedEx man shows up at his door with a book that has his entire life spread across 500 pages at a level of detail that would mess with anybody’s mind. There were things in there he didn’t remember or wished he’d forgotten.”

True to form, Westerberg isn’t commenting on the book now. Stinson also has declined requests for comment. While neither is likely to give it a glowing review, it’s possible in either case to see the nonresponse as an unofficial endorsement — as if they’ve now said all there is to say on the subject.