The two then head over to the water fountain they know will be nearby, and propped up next to it is a black trash bag. Something that appears to be blonde hair is sticking out. The music gets all dramatic for a moment as Catherine opens the bag, and then a sex doll pops out. Duh-DUNH-duh! Gil looks supremely peeved, and his voice reflects that as he snots, "He knew we would find this, and now he's taunting us." Catherine's got a look like, "Gil, that's just the reaction he wants. Don't give him the satisfaction."
And then those two head back to the lab for the second montage of the night. It's basically an excuse to show a sex doll on prime time network TV before the indecency fines triple for all offenses, real or imagined. And to bring in the cast of Stomp to run fingerprints through CODIS, if the soundtrack is anything to go by. Nicky works the railing during the montage; Catherine and Gil process the sex doll as if she were a real woman. (Insert your own Real Doll joke here.) Catherine eventually finds the folded-up note in the doll's mouth: it reads, "I HAVE HER."
Gil and Catherine look at each other, appalled by the realization that the Blue Paint Killer's got another victim. As Gil lifts a single human hair off the note, Catherine notes somberly, "Two years ago, DNA found a hair on Debby Reston that belonged to the serial's first victim, Janet Kent." Gil prods our memories of sweeps periods past with, "Planted hairs. It's his signature."
And then he goes to look at the note for a while. As Gil scans it, he shakes a little fingerprint powder on it, and shadows the impression of whatever was written on the page above the note. In this case, it's a drawing -- an amateurish facial study of a gagged blonde woman, with a tear spilling out of one eye.
Catherine confirms with the rest of the guys -- Sara is evidently still off having that coffee on Catherine -- that DNA confirmed the hair as belonging to Debby Reston. Gil points us all to the art -- which, in addition to its obvious Robert Crumb-like influences, also shows a similarly comix-influenced lack of proportion when it comes to head and limb size -- and says, "I tested the note with ESDA because I saw some indentations in the paper." Because this show sees no need to educate us on the actual forensics techniques used -- choosing instead to have characters like Warrick state the obvious with, "He must have written 'I HAVE HER' on an underlying page" -- I will tell you what ESDA is. The acronym stands for Electrostatic Detection Appartus, and it's one of two methods commonly used to recover indentations on sheets of paper. The paper with the latent writing is covered with a transparent material, which is fixed to the paper via vacuum drawn through an underlying porous bronze plate. This makes a tight covering-paper-plate sandwich, so the cellophane can prevent damage to the document. The sandwich is then subjected to a repeated high-voltage static charge, which creates a variably-charged surface; any impressions retain a heavier static charge relative to the flat paper. Black toner is then shaken over the surface, and it adheres to the charged area, effectively replicating the writing that caused the impression. The impressions are then photographed and preserved by covering the cellophane layer with an adhesive-backed clear sheet. As a result, the entire process is non-destructive to the original document.
Now that you know what ESDA is, now you also know that the CSIs used it to gaze upon some comix-inspired art. Catherine points out that prior investigations had concluded the killer was an artist or had some connection to the university's art department. Nicky notes, "Serials typically photograph their crime scenes. If we're dealing with an artist here, maybe he drew the crime scene instead." The CSIs all take a moment to thank their lucky stars they're not dealing with a macramé weaver. Then, because we haven't seen enough of this particular drawing, everyone analyzes it for a while. Warrick points out that it looks like the bound and gagged woman is in a small room. Gil wants to know what the small seat is in the foreground; Warrick thinks it's a chair or sofa. His interior design skills are tight, like his game. He's conscious of flow, and creating classic compositions balancing texture against shape. Oh, who am I kidding? Warrick is a shoe man. Nicky is the one you ask about interior design. Nicky notices the square window in the upper left corner, and after they blow it up, we see that it's backwards writing of some sort. Catherine figures it's some some sort of signage; Gil signals his contempt for the sign with, "The letters are backwards." Nicky dons the helm and mantle of alter-ego Snicky and says, "Cramped space, chairs in the foreground but no other furniture, no shutters or curtains on the windows. Maybe it's not a room. Maybe it's a vehicle."