He had been asleep on the floor of the attic for hours, but all of a sudden Gerald Foos jumped up, knelt on all fours and peered down through the vents into the motel room below, careful not to make a sound.
It was the moment he had been waiting for; his guests, a young, attractive couple, were engaged in a sex act below.
Rather aroused by the sensual display, Foos turned to his wife Donna who sat silently next to him, and they too began having sex while watching the strangers just metres below.
Welcome to the twisted life of the self-described "greatest voyeur in the world". You see, in the 1960s Foos had bought the 21-room Manor House Motel on Colfax Avenue in Aurora, Colorado, and promptly transformed it into an elaborate setup that allowed him to watch his guests' most private moments.
With the help of his wife, Foos fit more than a dozen rooms with large fake ceiling vents so he could spy on the guests, using pliers to bend the louvres to an angle that would hide his presence while giving him a clear view of the beds and bathroom doors.
"This trial-and-error process took us weeks," Foos confessed. "And it was exhausting - with me constantly going up and down between the attic and rooms, and my hands aching from all those adjustments with my pliers."
He placed three layers of thick carpet over the attic floor and even used rubber-tipped nails to help silence any footsteps from above. There were also "viewing posts" installed in several bathrooms, so he could monitor guests' bathroom habits.
Foos ensured that only young and attractive guests would be placed in the "viewing rooms", while families, the elderly or less attractive would be placed in one of the other "non-viewing" rooms.
He went on to watch hundreds of couples over the next few decades, until he sold his motel in 1995. He was never caught.
A secret life he was longing to share
Foos's strange story came to light this week due to an investigation by the New York Post. He had penned several letters to journalist and author Gay Talese since 1980, after reading his book Thy Neighbor's Wife, which explored America's sexual revolution.
Foos confessed that he bought the motel to fulfil his "uncontrollable desire to peer into other people's lives", and was convinced that his story would make a good book. And it turns out he was right, with the book The Voyeur's Motel detailing Foos's life set to be published on July 12 by Grove Atlantic.
Of the book, Foos says "It's my life - my secret life".
And as the hotel no longer exists (it was knocked down years ago), and the statute of limitations has passed for any crimes that he may have committed along the way, he agreed to let Talese reveal his identity.
Also, Foos believes he is a "sexual researcher and social observer" and the knowledge he gained from watching strangers having sex is a great benefit to mankind.
"He thinks he's the greatest voyeur ... He doesn't want to be seen as a peeping Tom but as a voyeur - not as a pervert but an observer of human nature," Talese said.
Not content with simply observing people, Foos had also kept a sordid journal of what went on in those rooms, calculating that within a few years he'd witnessed 296 sex acts, with 195 of them involving white heterosexuals, as well 184 male orgasms and 33 female orgasms.
He also categorised the participants as follows:
• "12 per cent of all observable couples at the motel are highly sexed."
• "62 per cent lead moderately active sex lives."
• "22 per cent are of low drive sexually."
• "3 per cent have no sex at all."
In a journal entry from 1977, Foos also claimed he witnessed a murder in the motel, with a male drug dealer strangling his girlfriend. However, there was no evidence to back this up and authorities have no record of such a crime. How much of what Foos claims is truth is not known.
As claims of witnessing suicide, robbery and rape emerged, Talese pondered whether Foos could be nearing a mental breakdown, with his description of his motel guests sounding more like thoughts from his own conscience, such as the time he wrote he felt "overwhelmed by the fantasy, the play-acting, and the game-playing of the real world".
As well as sending him 300 pages of typewritten manuscript over the years, Foos tried to convince Talese to come and check out his motel setup.
Intrigued, in the 1980s Talese agreed and joined Foos in his observation "laboratory" (the attic) to watch an attractive couple who'd just checked in after a ski trip. And in the process, almost got Foos caught out.
Talese said of the visit: "I saw what Foos was doing, and I did the same: I got down on my knees and crawled toward the lighted louvres. Then I stretched my neck in order to see as much as I could through the vent, nearly butting heads with Foos as I did so.
"Finally, I saw a naked couple spread out on the bed below, engaged in oral sex. Foos and I watched for several moments, and then Foos lifted his head and gave me a thumbs-up sign. He whispered that it was the skiing couple from Chicago.
"Despite an insistent voice in my head telling me to look away, I continued to observe, bending my head farther down for a closer view. As I did so, I failed to notice that my necktie had slipped down through the slats of the louvred screen and was dangling into the motel room within a few yards of the woman's head.
"I realised my carelessness only when Foos grabbed me by the neck and, with his free hand, pulled my tie up through the slats."
He had witnessed the setup with his own eyes, Foos was telling the truth about this aspect, at least. As for the rest of his stories, we may never know ...
A chilling diary entry
We'll leave you with a journal entry dated November 24, 1966, where Foos describes using the "viewing platform" for the first time. It's quite, well, descriptive:
"Subject #1: Mr. and Mrs. W of southern Colorado.
"Description: Approx. 35 year old male, in Denver on business. 5'10", 180 pounds, white collar, probably college educated. Wife 35 years old, 5'4?, 130 lbs, pleasing plump, dark hair, Italian extraction, educated, 37-28-37.
"Activity: Room #10 was rented to this couple at 7pm by myself. He registered and I noticed he had class and would be a perfect subject to have the distinction of being #1. After registration, I immediately left for the observation walkway. It was tremendous seeing my first subjects, for the initial observation, enter the room.
"The subjects were represented to my vision, clearer than anticipated ... I had a feeling of tremendous power and exhilaration at my accomplishment. I had accomplished what other men had only dreamed of doing and the thought of superiority and intelligence occupied my brain.
"As I peered into the vent from my observation platform, I could see the entire motel room, and to my delight the bathroom was also viewable, together with the sink, commode, and bathtub ... I could see the subjects below me, and without question they were a perfect couple to be the first to perform on the stage that was created especially for them, and many others to follow, and I would be the audience.
"After going to the bathroom with the door closed, she sat in front of the mirror looking at her hair and remarked she was getting grey. He was in an argumentative mood and appeared disagreeable with his assignment in Denver. The evening passed uneventful until 8.30pm when she finally undressed revealing a beautiful body, slightly plump, but sexually attractive anyway. "He appeared disinterested when she laid on the bed beside him, and he began smoking one cigarette after another and watching TV ... Finally after kissing and fondling her, he quickly gained an erection and entered her in the male superior position, with little or no foreplay, and orgasmed in approximately five minutes. She had no orgasm and went to the bathroom ...
"Conclusion: They are not a happy couple. He is too concerned about his position and doesn't have time for her. He is very ignorant of sexual procedure and foreplay despite his college education. This is a very undistinguished beginning for my observation laboratory ... I'm certain things will improve."