Dark Rivers of the Heart

checked steel, but no smooth steel."
        "Too bad," Roy said.
        "Too bad?" Davis said, eyes widening as if Roy had responded to news of the Pope's assassination with a shrug and a chuckle. "It's as if the damned thing was designed for burglars and thugs-the official Mafia flashlight, for God's sake."
        Wertz mumbled an affirmative, "For God's sake."
        "So let's do the window," Roy said impatiently.
        "Yes, we have big hopes for the window," Davis said, his head bobbing up and down like that of a parrot listening to reggae music.
        "Lacquer.
        Painted with multiple coats of mustard-yellow lacquer to resist the steam from the shower, you see. Smooth." Davis beamed at the small window that lay on the marble lab bench. "If there's anything on it, we'll fume it UP."
        "The quicker the better," Roy stressed.
        In one corner of the room, under a ventilation hood, stood an empty ten-gallon fish tank. Wearing surgical gloves, handling the window by the edges, Wertz conveyed it to the tank. A smaller object would have been suspended on wires, with spring-loaded clips. The window was too heavy and cumbersome for that, so Wertz stood it in the tank, at an angle, against one of the glass walls. It just fit.
        Davis put three cotton balls in a petri dish and placed the dish in the bottom of the tank. He used a pipette to transfer a few drops of liquid cyanoacrylate methyl ester to the cotton. With a second pipette, he applied a similar quantity of sodium hydroxide solution.
        Immediately, a cloud of cyanoacrylate fumes billowed through the fish tank, up toward the ventilation hood.
        Latent prints, left by small amounts of skin oils and sweat and dirt, were generally invisible to the naked eye until developed with one of several substances: powders, iodine, silver nitrate solution, ninhydrin solution-or cyanoacrylate fumes, which often achieved the best results on nonporous materials like glass, metal, plastic, and hard lacquers.
        'The fumes readily condensed into resin on any surface but more heavily on the oils of which latent prints were formed.
        The process could take as little as thirty minutes. If they left the window in the tank more than sixty minutes, so much resin might be deposited that print details would be lost. Davis settled on forty minutes and left Wertz to watch over the fuming.
        Those were forty cruel minutes for Roy, because David Davis, a techno geek without equal, insisted on demonstrating some new, state-of the-art lab equipment. With much gesticulating and exclaiming, his eyes as beady and bright as those of a bird, the technician dwelt on every mechanical detail at excruciating length.
        By the time Wertz announced that the window was out of the fish tank, Roy was exhausted from being attentive to Davis. Wistfully, he recalled the Bettonfields' bedroom the night before: holding lovely Penelope's hand, listening to the Beatles. He'd been so relaxed.
        The dead were often better company than the living Wertz led them to the photography table, on which lay the bathroom window. A Polaroid CU-5 was fixed to a rack over the table, lens downward, to take close-ups of any prints that might be found.
        The side of the window that was facing up had been on the inside of the bungalow, and the mystery man must have touched it when he escaped.
        The outside, of course, had been washed with rain.
        Although a black background would have been ideal, the mustard-yellow lacquer should have been sufficiently dark to contrast with a frictionridge pattern of white cyanoacrylate deposits. A close examination revealed nothing on either the frame or the glass itself Wertz switched off the overhead fluorescent panels, leaving the lab dark except for what little daylight leaked around the closed Levolor blinds.
        His pale face seemed vaguely phosphorescent in the murk, like the flesh of a creature that lived in a deep-sea trench.
        "A little oblique light will make something pop up," Davis said.
        A halogen lamp, with a cone-shaped shade and a flexible metal cable for a neck, hung on a wall bracket nearbyDavis unhooked it, switched it on, and slowly moved it around the bathroom window, aiming the focused light at severe angles across the frame.
        "Nothing," Roy said impatiently.
        "Let's try the glass," Davis said, angling light from first one direction then