In looping black fountain pen on paper now browned and cracked at the edges, a grim story unfolds:

“Both thoracic . . . cavities contain a large amount of blood, the lungs are perforated 12 times, there is laceration of the thoracic aorta, laceration of the liver and of the diaphragm.”

That’s what became of Reinhardt Schwimmer, a North Side optometrist charmed by the trappings of gangster life and slain in one of the grisliest chapters in the city’s history: The St. Valentine’s Day massacre of 1929.

For decades, Schwimmer’s autopsy report — as well as those of the six other victims in the massacre — had been all but forgotten, gathering dust in a metal file cabinet in a Cook County government warehouse.

Enter James Sledge, the county medical examiner’s executive officer. A local history buff and Chicago native, Sledge joined the office in 2014 and soon asked if he could have a look at the autopsy reports from an attack widely believed to have been ordered by Al Capone.

It took Sledge’s staff multiple trips to the warehouse to find all of the reports, which have now been assembled with the transcripts from the public inquest into the slayings. Sledge and his office are considering where best to keep the newly discovered documents.

“I felt a little chill down my back,” Sledge said this week, recalling seeing the paperwork for the first time. “The reports are very graphic about what happened. You read about history, you talk about it, but to have something in your hands — it gives you an odd feeling.”

By the late 1920s as the gangland wars raged, Chicagoans had become accustomed to newspaper images of sheet-covered corpses and automobiles riddled with bullets holes.

Police and people gather in front of the S.M.C. Cartage Co. garage on North Clark Street after the Valentine's Day massacre. | Chicago History Museum/Distributed by AP

Police and residents gather in front of the S.M.C. Cartage Co. garage on North Clark Street after the St. Valentine’s Day massacre. | Chicago History Museum/Distributed by AP

But nothing could quite prepare the public for what happened on the morning of Feb. 14, 1929, inside a Lincoln Park garage on Clark Street. On the other side of the blacked-out garage windows, coffee bubbled on a stove. The men inside chomped on crackers and got on with the business of the day. Five of the men were well known to police — gangsters working for George “Bugs” Moran, an irascible rival to Capone. A mechanic in overalls milled about the garage, Moran’s headquarters. Reinhardt, who had no criminal record but liked to pal around with Moran’s crew, was there too.

The front door of the garage opened. Two men in police uniform marched in. Two more men in civilian clothes followed. The men carried shotguns and submachine guns. The intruders ordered the men inside to get on their feet and line up against a wall in the garage. There was no evidence of a struggle. Likely, Moran’s men thought it was a raid and they were about to be arrested.

The New York Times described what happened next as “the most cold-blooded gang massacre in the history of this city’s underworld.”

When the smoke and brick dust settled, some 160 empty machine gun shells lay strewn across a concrete floor glistening with rivers of blood.

“The roar of the shotguns mingled with the rat-a-tat of the machine gun, a clatter like that of a gigantic type-writer,” a New York Times reporter wrote.

Beneath its banner “Massacre” headline, The Chicago Daily News wrote: “Killing scene too gruesome for onlookers.”

Suspicion quickly drifted Capone’s way. But he had an alibi: He was at his winter home in Florida.

“It’s a war to the finish,” Chicago Police Commissioner William F. Russell told reporters at the time. “I’ve never known of a challenge like this — the killers posing as policemen — but now the challenge has been made, it’s accepted. We’re going to make this the knell of gangdom in Chicago.”

The crime was never solved.

A body is removed from the S.M.C. Cartage Co. garage on North Clark Street in Chicago on Feb. 14, 1929 following the St. Valentine's Day massacre. | Chicago History Museum/Distributed by the Associated Press

A body is removed from the S.M.C. Cartage Co. garage on North Clark Street in Chicago on Feb. 14, 1929, following the St. Valentine’s Day massacre. | Chicago History Museum/Distributed by the Associated Press

The documents now in Sledge’s possession offer a fascinating picture of the 87-year-old investigation, with details ranging from the tragic to the mundane to the comic.

There’s an inquest interview with Schwimmer’s bereft mother, in which the coroner, Herman Bundesen, gently prepares the witness for what’s to come.

“Now, we won’t ask you any more questions than are necessary, and you try to brace yourself as well as you can . . . ,” Bundesen tells Josephine Schwimmer.

Schwimmer talks about her son’s devotion, noting that she saw him “every day,” and had been giving him a little money to tide him over until he could find a new optometry office.

And she told investigators she didn’t believe he’d been in any kind of trouble, although she knew her son’s taste in friends.

She said her son had sold Moran some eyeglasses and had gone to baseball games with him.

“As I say, he lots of times paid for things,” Schwimmer said. “He wanted to accommodate that crowd.”

At the end of the hand-written autopsy report, it says simply, apparently in Schwimmer’s own hand: “I will bury remains.”

The transcripts from the inquest also highlight the difficulties investigators faced in solving the crime: witnesses too afraid to testify, the limits of the forensic science of the day and the gangsters’ loved ones claiming to know nothing of their family member’s line of work.

In one transcript, the coroner urges the salivating members of the press to behave themselves.

“It is requested, and I have asked the newspaper boys not to take any flashes until we get set. . . . We want to get along with you boys,” the coroner says.

What Sledge finds fascinating, among other things, is how little reporting from crime scenes has changed through the years.

“Forensic science has continued to evolve over the last 100 years with a lot of advancement, but at the end of the day, when you talk about cause and manner of death and the way we describe gunshot wounds, they are remarkably similar,” Sledge said.

Fountain pens have since been replaced by computer keyboards, he noted.

Now that the St. Valentine’s Day massacre papers have been retrieved from the shadows, Sledge said, he’s weighing what to do with them.

“On the one hand, we want to have them readily available,” Sledge said. “But we don’t want them so accessible that we in some way anger some part of the population who feel we are not paying proper respect to the deceased.”