In all, eight people were killed by inmates at Alcatraz. One guard was murdered in an assault in the prison's laundry room in the late 1930s, and two others died during an attempted breakout in 1946. Five inmates were killed in random attacks. Five other prisoners committed suicide.
DeVincenzi witnessed a killing on his first day as a guard. He'd been assigned to the prison's barbershop. Easy duty, he figured. Early in his shift, as he was watching an inmate shave another with a straight razor, all hell broke loose.
"The barber's name was Freddie Lee Thomas, and suddenly he takes his shears and starts stabbing the man in the chair," DeVincenzi recalled. "He's slashing his neck and arms, and I'm blowing my whistle. Within moments, the man is dead, lying in a pool of blood. I guess the two were lovers.
"Freddie hands me the bloody shears. Then he leans over the body and kisses the dead man on the forehead. "Goodbye," he said. "I love you."
Years after the prison shut its doors, the island's sense of seclusion remains. Until the use of cellphones, night watchmen relied on a dated ship-to-shore phone to reach the mainland, making many feel marooned at sea.
Erik Novencido worked the island night shift for 10 years. The worst part was walking inside the electroshock therapy room. Once he took a picture at night to show friends. When he developed the film, he says, the snapshot showed a face in the room staring back at him.
He never figured out what it was.
"Sometimes I was just overwhelmed by fear," he said. "The rangers told me stories about the things that happened here. And I'd say, 'Keep that to yourself. I've got my sanity to keep.' "
Veteran park ranger Craig Glassner has been afraid even during the day. "Once on an isolated spot I heard this 'Whooooo, whooooo,' like someone blowing on a big Coke bottle," he said.
"I thought, 'Do I run?' Then I saw it was the wind blowing across the stanchions of a fence. It really freaked me out."
Mary McClure, who spent 12 years working nights on Alcatraz until last fall, preferred the isolation. She couldn't wait for the last tourist to leave. "It was the standard fantasy of being alone on an island," she said. "Well, maybe not Alcatraz."
Even so, there were strange events. "Many times, at night in the cell house, I had the distinct sensation of being pinched on the butt," said McClure, 52, a former paramedic. "It happened with great regularity. I have no explanation for it, and I don't talk to people about it, because I know it makes me sound crazy."
Former inmate John Banner spent four years here in the 1950s. He still recalls the squeal of the wind at night.
"Laying awake, listening to that wind, trying to hold on to what sanity I had left, I always thought of the brutality of that prison," said the convicted bank robber, who lives in Arizona.
Now 83, Banner can't imagine facing Alcatraz alone, at night. "I don't believe in spooks," he said, "but why on earth would a person want to do that?"
WHEN darkness comes, you don't leave Alcatraz; you flee.
Amid a driving rain, a ranger hands Johnson the keys to the island — hurrying toward a ferry that soon whisks away the last of the day's 5,000 visitors.
Johnson stands solitary amid the gathering seagulls. The big birds are now everywhere, lined up on walls, circling like vultures.
They make him uneasy.
"It's like they're watching me, to see if I'm going to crack," he says, "like in that Alfred Hitchcock film, 'The Birds.' "
He makes a sweep for any tourist stragglers and settles in for the long night.
Johnson's father was a prison guard in upstate New York. He has the job in his blood. But Alcatraz is different.
The last rays of sun now gone, the island fortress becomes a grim, humorless place, the stuff of black-and-white 1950s crime photos. Johnson plays upbeat music on his iPod — Prince, Wham, Michael Jackson — to lighten the gloom.
He earns overtime pay for his 18-hour shifts (3 p.m. to 9 a.m.), but sometimes, in the dead of night, he says, "it seems like blood money."
At 8 p.m., dressed in a black cap and windbreaker, his radio squawking with park police chatter, Johnson winds his way up a switchback as birds dive-bomb from ledges. In the rain, the cell house looms up ahead like a haunted castle.
He walks cellblock rows that inmates nicknamed Broadway, Sunset Alley and Seedy Street. He enters a solitary cell, its heavy iron door creaking. The tiny quarters remain perfectly black even after his eyes grow accustomed to the space.
He stops at the cell of Frank Lee Morris, whose daring breakout was immortalized in the film "Escape from Alcatraz." Morris and two others left inside their cells dummy heads fashioned out of soap and toilet paper — complete with hair from the barbershop. The idea was to fool guards while they left through holes chiseled in their cell walls.
Johnson looks at a model of one fake head left in the cell as a tourist display. He knows how the men felt: "Ten years here? I'd go crazy before that."
By dawn, the night watchman is weary of the Rock. Passing the keys to a ranger, he makes his own escape from Alcatraz, the sun on his face.