THE SOMERVILLE POLICE DEPARTMENT is a low concrete structure that looks like a small town library from the 1960s, with a fenced-in yard containing a fleet of half-serviceable patrol cars and a steep concrete ramp out front that leads to a walled parking lot. Right at noon, thirty-nine-year-old Joe McCain, Jr., pulls up and I climb in the passenger side of the sump-smelling cruiser and buckle myself in. Since we're working together and so much of the “cop job” spills over to the P.I. firm, McCain has suggested I ride along with him on his shift as a police sergeant and hear about a few past cases while getting familiar with the territory. He shakes my hand with a grip like a wrestler and pushes off beneath gloomy skies, past the convenience stores, pawnbrokers, and blocks of crowded tenements.

Two of the many truths contained in the hard-boiled detective oeuvre are that there's no money in it and a whole lot of sitting around. In Raymond Chandler's The Big Sleep, Philip Marlowe says, “I went back to the office and sat in my swivel chair and tried to catch up on my foot-dangling.” As a working cop, Joe McCain has a distinct advantage over the classic gumshoe: instead of dangling his feet inside the Fulton Street office of McCain Investigations, four out of every six days he puts on a bulletproof vest, straps on his gun, and hits the pavement equipped with an up-to-the-minute criminal database and supported by 130 well-armed, well-trained partners. There's no down time on the streets of Somerville.

Just looking at him, Joey McCain is the kind of guy somebody would tire of knocking down long before he'd stop getting back up. He's a former U.S. Marine, a graduate of the University of Massachusetts–Boston, and possesses a master's degree in criminal justice. A compact, powerful man with a shaven head and neatly trimmed mustache, McCain is covered in tattoos, from his neck to his ankles. As he rides through Porter Square, he keeps up a running commentary on past investigations while peering into alleyways and sizing up the other drivers and their passengers.

Standing outside her Brazilian eatery, a tall, attractive female shopkeeper with a circle of bright lipstick whistles at McCain and waves. “What's up?” he asks through his open window. The woman smiles and blows him a kiss.

Not an especially large man, McCain is a presence nevertheless; he has the swagger of a city cop leavened with sympathy for those who are growing up on the same streets he did. He says he owes it all to his late father, who was his hero, mentor, and best friend. “He knew how to relate to people from all walks of life: doctors to dockworkers,” says McCain. “That was his secret.”

Very often, great dads are easier to lionize in death than they are to emulate in life. Being “Junior” is a hump some guys never get over, and they go running to another part of the country, a different sort of career, a new life. But Joe McCain, Jr., is not awed or intimidated by the legend of his father. Under the rough talk and the lurid swirl of tattoos, including a vengeful ex–undercover cop from Marvel Comics named “the Punisher” that fills his entire back, Joey's a character in his own right. He's also a guy who put on the uniform, staked out a piece of turf, and assumed the mantle of his old man out of respect, not as a way of keeping up. If you know Joey McCain, you can't imagine him doing anything but this: investigating crimes and putting away bad guys right where his father started, more than forty years ago.

Incorporated in 1842, Somerville is a city of four square miles and roughly 80,000 people, located along the northern edge of Boston. Once a stronghold of Irish and Italian immigrants, Somerville today is a mélange of over fifty nationalities, a diverse mix of students, shopkeepers, blue-collar and bohemian types, and a couple of posh, leafy neighborhoods bordering the campus of Tufts University. Guys like Joey McCain and his fellow P.I. Mark Donahue grew up playing baseball at Trum Field; went to Somerville High; swam at the Dilboy pool and learned to skate at the MDC rinks; drank beer in the McCain basement; and shot thousands of pucks off a sheet of plywood in the McCain driveway. Donahue eventually moved his family out, to suburban Methuen. But Joey McCain has always called Somerville home.

“I love the Somerville of today,” says McCain. “The arts, the entertainment, the restaurants. You just gotta keep your eyes open.”

In Teele Square, where several nondescript storefronts lie opposite a city firehouse, McCain tells me about the day in April 1999 that he was riding his bicycle on a community policing detail and came upon a joint called the Station Café. Piqued by something, he rode up to the entrance, dismounted his bike, and peered into the front window. The barroom was filled with Hells Angels and Outlaws, rival motorcycle gangs that were locked in a mortal struggle for the New England drug trade and that never, ever socialized together.

McCain has a long, bad history with the Hells Angels, who have at various times threatened him, his friends, and his wife and three children. Although he has dabbled in things such as scuba diving, marathon running, and playing drums in a jazz band, the one true passion of Joey McCain's adult life is motorcycling. He's been riding since he was nine years old, when his father bought him a used Yamaha 80. Today he own a KDX 200 Kawasaki dirt bike, a '92 K75S BMW street bike, and a '99 Electra Glide Standard Harley-Davidson. All three of his sons— Joseph, age eleven; Liam, nine; and Lucas, six— have their own motorcycles. And McCain is a card-carrying member of the Renegade Pigs, a national organization of police and firefighters that ride American-made motorcycles. The Renegade Pigs are composed of twenty-five chapters, including two in Massachusetts, and over five hundred members.

“Some people, even other police officers, categorize us as rogue cops, because we're heavily tattooed and wear leather vests,” says McCain, cruising down Powderhouse Boulevard, alongside the flat, green planes of the Tufts athletic fields.

But the Renegade Pigs are nothing more than a group of law enforcement types who blow off steam by riding their Harleys, camping out, and drinking beer, McCain says. The enmity between Joe McCain, Jr., the Renegade Pigs, and the Hells Angels began in the mid-nineties, when McCain gave an interview to a New Hampshire newspaper that disparaged the Angels.

“I said that they were punks and drug dealers, and the funniest thing about it was, they didn't object to being called drug dealers, just punks,” McCain tells me.

After the story was published, an accompanying photograph was passed around Angels' haunts, and word came down that Joe McCain should start watching his back. Friends said that his photo was hanging up in an Angels' clubhouse with a red line through it, that there was a bounty on him, and that Angels were competing to see who would strip the Renegade Pigs' insignia from Joey's leather jacket.

Estimates of the Hell Angels' involvement in the illegal methamphetamine trade nationwide are as high as 75 percent, McCain says, and they also traffic in cocaine, marijuana, prostitution, and the “chopping” and reselling of stolen motorcycles. Recent efforts to legitimize their existence by retailing club paraphernalia and portraying themselves as the last free Americans are nothing but a smoke screen for their true identity, according to McCain.

“They are the dregs of society,” he says. “Stop me when I'm lying, is what I always say to them. They're nothing more than a fascist regime.”

By the late 1990s, the Hells Angels were upset with the Renegade Pigs for a number of reasons, including the law enforcement group's habit of wearing their chapter name in semicircle formation on the back of their vests, an Angel practice that other clubs are “forbidden” to emulate. Then one night, just a few hours after someone in New York had affixed a Renegade Pigs sticker to a Hells Angels' motorcycle, a small group of the Pigs left the Red Rock bar in Manhattan's Meatpacking District. A dark blue SUV cruised up alongside them, the tinted windows came down, and someone inside the van opened fire.

“They shot a Washington, D.C. cop, in the ass, Dave Moseley, a buddy of mine,” says McCain. No one was ever arrested for the shooting, but “it was definitely the Angels,” he says.

It was against this backdrop that Joe McCain, Jr., rode up that night in April to the entrance of the Station Café. Seated at two tables pushed together in the rear of the saloon were approximately ten members of the Hells Angels and a dozen Outlaws, gangs that had been killing each other since the 1970s. Immediately, McCain radioed his division commander for backup units and asked that they keep out of sight.

Although the two gangs have always hated each other, their operations had been sufficiently undermined by law enforcement that they had convened to discuss a truce. As luck would have it, their sworn enemy, Joe McCain, Jr., working alone, had discovered the proceedings.

His heart hammering in his throat, McCain pushed open the door and went inside. “I felt like those guys in Animal House, when they walk into the bar and they're the only white guys,” says McCain.

He passed through a small alcove, which was clad in dark 1970s paneling and badly lit; to his right was the long wooden bar and to the left a narrow room outfitted with benches and booths lined up along the wall. Every biker in the place turned and watched him come in, dressed in shorts and boots and wearing his badge and gun.

“Anyone with a brain in his head was finishing his drink and trying to leave as unnoticed as possible,” says McCain.

As he neared the table, an Outlaw rose from his seat. A well-muscled, stocky man with thick shoulders and a military haircut, the gang member was a former corrections officer and Army Ranger whom McCain had been introduced to while hobnobbing at a local Harley shop.

“Hello, Joe,” said the Outlaw, shaking McCain's hand. “There won't be any trouble here, and we'll be gone in half an hour.”

McCain reinforced the notion that he didn't want any trouble, and that he wanted the gang members out of the neighborhood. Then he turned around and walked out.

This was unbelievable; the Angels and the Outlaws were having a summit in a public bar while offering peace terms to law enforcement. “I live near there, and I left my bike, went around the corner to my house and got my video camera, and went over to the firehouse across the street,” says McCain. “I asked the guys there if I could get to the upper floor and hauled ass up the stairs. A little while later, the Angels and Outlaws started piling out of the bar, laughing like they're all great buddies now. You gotta see it.”

We're approaching the end of McCain's shift, so we return to the station, park the cruiser in the lower lot, and enter through a reinforced door next to the mechanic's bay. As we pass through the dispatcher's area, where detailed maps of Somerville are pinned to the wall and a steady stream of radio traffic is heard, a tall, burly E-911 operator named Scott Lennon hails McCain. “You guys ready to eat?” he asks. “I'm starving. My stomach thinks my throat is cut.”

McCain laughs. “Yeah. Let's get some chow.”

In the division commander's office, Joey rigs up his video camera on the desk and rummages through a cardboard box for the Hells Angels tape. On top of a nearby file cabinet is a set of women's clothing in a stapled plastic bag, the evidence from a rape the night before. One of the dispatchers comes in and mentions that the rest of the rape kit is in the freezer down the hall. McCain continues searching until he finds the right tape, and then Lennon enters with the food: wire-handled containers of rice, mushy vegetables in sweet sauce, and candied pork and chicken from the Thai place across the street.

McCain finishes cueing up the tape, and we sit there with steaming plates of rice and chicken balanced on our knees. The Station Café is a long, yellow brick building with two picture windows fronting on Holland Street. The camera zooms in, panning across six husky figures in leather vests clustered around the bar. The “rockers” sewed onto their vests indicate that four of the men are Hells Angels and two are Outlaws. McCain's voice is heard on the tape, as well as that of a fireman who is standing beside him.

You don't usually see them together, the fireman says.

Never, McCain says. Something's up, for sure.

The camera settles on the Victorian-looking door, which contains a sheet of etched glass that doesn't allow a clear view into the bar. On tape, McCain says, C'mon, you guys. I want everybody to come out, so's I can . . .

In a moment the door opens and a huge, bald-headed Outlaw with a thick gold chain exits the bar, laughing with two Angels and an Angel prospect, identified as such because he lacks an upper rocker on his vest. As the gang members pass into the evening, McCain frames a nice, tight shot on each of their faces.

Outlaws and Angels smiling and joking, says McCain on tape. I love it.

Because of his own rightful distinction between motorcycling enthusiasts and what he calls “criminals disguised as bikers,” McCain takes genuine pleasure in deflating the Angels. One after another they cross the threshold of the barroom like they're being introduced on a TV show, and Joey says, “Thank you, thank you, and thank you,” as each man scowls into the camera.

Just then two Angels with long shaggy hair come outside. They are dressed in black jeans, black, long-sleeved T-shirts, and their vests, and are smoking cigarettes. One of them spots Joe's bicycle, which is still leaned up near the entrance, and he nudges the other gang member, exhales a plume of smoke, and says something. In a juvenile show of defiance, the Angel pantomimes getting on Joey's bicycle, and he and his crony roar with laughter.

“Tough guys. Except they're so fucking stupid they can't tell they're getting their pictures taken,” McCain says to me.

While we're watching the tape, Joe McCain's phone rings; he picks it up, growls his name, and immediately drops into a more pleasant register. It's his mother calling. Helen McCain, sixty-six, a retired nurse and widowed for a year, is having a rough day. Today would have been Joe Sr. and Helen's forty-second wedding anniversary, and next week is the first anniversary of his death.

Joey speaks with his mother for a few minutes and promises to look in on her when his shift is over. Other than breaks for college and the Marine Corps, Joe McCain has lived in the house where he was born his entire life. The McCain residence is right off Powderhouse Boulevard in West Somerville, in a neighborhood bordering on the Tufts University campus and composed of half-million-dollar homes dating back to the Grover Cleveland administration.

“It used to be, in the thirties, forties, and fifties, that three generations would stay together as a single family unit,” McCain tells me. “That's the main reason we stayed in Somerville: I wanted to raise my kids in the same house as the greatest guy in the world, my father.”

Just to give me an idea of the influence his dad had on him, as well as the impact of the old man's death on such a wide range of people, Joey McCain has shown me the notes he kept while sitting beside his father's bed in Mount Auburn Hospital last fall. The day before he died, Joe Sr. was lying on the ward listening to jazz music with his only son and telling stories about the old days. During the gangland murders back in the late fifties and early sixties in Somerville and Charlestown, Joe Sr. was a key witness for the prosecution. Joey writes:

At the conclusion of his shift, Joe McCain takes me through the dispatcher's room, into a dingy hallway and out past the lockup. We pause at the head of the corridor that runs between the jail cells, empty but for a pair of boots and rumpled clothes set on the floor. They belong to the unit's sole prisoner.

“Hey, Richard,” says McCain, hailing the guy in the cell. He's a regular tenant here, a fifty-year-old wheelchair-bound man who likes to get drunk and roll into traffic and has been in protective custody for forty-eight hours.

A man's voice echoes from the last cell. “What?”

“Where's your chair?” McCain asks.

“I don't know.”

McCain stands there with his hands on hips, glancing into a nearby closet and down the adjoining hallway. “Well, we're gonna give you a fucking bicycle and you can pedal it with your hands,” he says.

The prisoner laughs and swears at us and we duck out of the corridor and McCain presses a button on the wall and the heavy steel door of the mechanic's bay climbs up its track. We emerge onto the lot, and as we go across the wet pavement, my head is teeming with Angels and Outlaws and Rocco Petricone and big Joe McCain dying at Mount Auburn and Chet Baker at the end of his life playing “My Funny Valentine.” Like it or not, realize it or not, life is about measuring up, finding out whether you can hang with the big boys. I wonder aloud what use I'm going to be at McCain Investigations. I have no law enforcement training and no real connections in the city, other than reporters at a couple of newspapers.

Joey McCain laughs and tells me not to worry about it. “Cops notoriously think they know everything,” he says. “We'd rather have a college guy who doesn't know a thing, so we can teach him the job.”

“When are we going to get a case?” I ask, getting into my car.

McCain grins at me. “Soon,” he says.

As I weave my way through the jumble of old paved-over cart paths that form the nexus of downtown Somerville, past the muffler shops and taverns and the boarded up frontage of the Union Square Redemption Center, it occurs to me that I've got my first case: looking for Joe McCain, Sr.

On the night that his father died, Joe Jr., his fellow P.I. Mark Donahue, and another Somerville cop named Mike Mulcahy drove out to visit big Joe's old partner, Leo Papile. In Leo's reckoning there were two kinds of people in the world— cops and assholes. The seventy-seven-year-old retired detective lived alone in a modest, brick-faced Colonial just over the Neponset Bridge in Quincy. He and Joe Sr. had worked MDC cases together for over a decade, locking up shitbirds of every variety: bank robbers, murderers, drug dealers, pedophiles, even dirty cops. Leo was Joe McCain's comrade in arms, his best friend, and as young Joey knocked on the door, hauling along a bag full of imported beer, he swallowed hard and set his jaw.

Tall and slender, Leo had always been well-dressed and well-groomed, with the slicked down look of the old Vegas Rat Pack, clean shirt, nice tie, his hair shining and parted to one side. But when he opened the door on Joey and his friends, he was an old man in battered pants and a mothy brown cardigan, rheumy-eyed, his hands shaking. Nothing inside the house had changed since Leo's beloved wife, Susan, died of cancer in 1973. The kitchen floor was still covered in the original worn linoleum. Around the table were metal chairs with hard vinyl seats, and the wooden cabinets and simple black clock were right out of the mid-seventies; even the color scheme was from another era, everything in brown, light green, and yellow. It was like time had stopped.

The men all shook hands. The beer came out of the bag, and someone fumbled through the drawers for an opener. Leo was a good-hearted, friendly man but abrupt and rather gruff. At a banquet one time he found himself sitting beside the mother of Joey McCain's former girlfriend. “Do you know who I am?” he asked. “No,” the woman said. “I'm afraid I don't.” Leo glared across the table at the younger McCain. “Joey, who is this fucking broad?”

On this particular night, Leo is adamant about the ground rules for big Joe's funeral. “There'll be no crying,” he says. “There's gonna be no bullshit.”

Suddenly he rises from the kitchen table. “Let me show you guys something. Come here. Come in here,” says Leo in his husky voice, leading his visitors into the next room. Spread over the dining room table are a raft of newspaper clippings, about his son Leo Jr., who is director of player personnel for the Boston Celtics, and stories about his grandchildren playing high school and college sports. When he wants to visit that part of his life, Leo explains, he goes into the dining room.

“Come over here,” Leo says. He directs the three men back into the kitchen and opens up a cabinet just to the right of the sink. Taped on the back are three calendar pages, two of them yellowed and one from the current month. The first is from March 1973, with a date circled in red.

“See this right here?” Leo asks. “This is the day my wife died. And this other one, this is the day I retired from the cops— a job that I loved.” The retired detective stabs his finger at the third calendar page, October 22, 2001. “And this is the day Joe McCain died. There are just three days. Guys, that's my life right there.”

Four months later, Leo Papile himself would be dead.

There's steady drizzle over Somerville now, as I drive by the Boys & Girls Club and beneath the railroad underpass, a steady mist falling on heavily laden trees and the streets gleaming in the wet. Detectives are in the business of reconstruction, piecing together crime scenes, motives, patterns of behavior, even the trajectory of a life when the situation calls for it. But when I think of Leo Papile and his calendar pages, I can't help recalling something else that Joey had written about his father when he was laying up in that hospital bed at Mount Auburn.

I believe those words, and try like hell to live by them myself. And as I set out on my year at McCain Investigations, it occurs to me that my most difficult case will be reconstructing the life of Joe McCain, Sr., to conduct my own private investigation into the force of his personality and so come to know the man after he has gone.