Guerrilla Art: An Artistic Whodunnit in Boulder, Colorado BOULDER, Colo. -- An artistic whodunnit that involves 500-pound sculptures appearing overnight and cryptic drawings delivered by mail is delighting this university town. The mystery began last month when Donna Coughlin glanced out the window in the wee hours and thought, "What is that?" It was a 15-foot-tall sculpture and had been silently placed on her front lawn. The artwork consists of a steel-reinforced post set in a concrete base. At the top is a collage of rusty chains and metal objects, a padlock, a socket wrench and a solar light that illuminates it after dark. "Detectives can't figure out how they got the darn thing in there without leaving any drag marks behind," Boulder Police Cmdr. Kim Stewart told the Daily Camera newspaper. The second sculpture appeared outside the Boulder History Museum three days later, on Dec. 14. It was similar to the first, but this one had skis, a child's bicycle tire, a hedge trimmer and other objects at the top. There was no artist's name on either piece, but there was a calling card of sorts. Both sculptures came with a tin box that contained a note written in letters cut from a magazine that read: "I hope u enjoy this thing," signed with the letters "PS." And both contained pairs of handmade earrings: one pair with Coughlin's sculpture, two with the museum piece. All was quiet for about a month. Then a woman who had praised the art on a news channel's website received a package in care of the station. Back in December, "madisonrenee186" had written: "That's hilarious! I'd love that! Hey artist person, I like earrings too!!" The package delivered Jan. 12 to 9News in Denver was presented to 25-year-old Madison Upton on the air. It contained a framed 18-by-18-inch drawing with 100 unique doodle-like symbols arranged in rows of 10, as well as a pencil sketch of a man pointing to the sculpture. A pair of earrings was attached. A similar piece was mailed to Jonathan Sackheim, 34, but under his name it said "in care of Bianca Parra." Parra is an art student at the University of Colorado at Boulder and did not know Sackheim. Like any good mystery, there are those who would like to solve the puzzle and those who are content to simply enjoy it. But all indications point to sculptor Mark Guilbeau, who received a master of fine arts degree from UC in 1987. Although Guilbeau's initials are not "PS," he was caught red-handed doing this type of thing in 1987 and became known as the "Phantom Sculptor." In fact, it was Coughlin who caught him. Back then, Coughlin found a sculpture in the shape of a giant bug on her lawn. It, too, came with a box that contained a pair of handmade earrings. The artist might have remained unknown except that two weeks later, Coughlin awoke in the middle of the night and caught Guilbeau and some friends disassembling it. He invited her to an art show, after which the two lost touch. Coughlin is convinced that it's Guilbeau again. She speculates that he picked her lawn because she lives on a corner lot. "It is kind of cool," Coughlin, 80, said in an interview with AOL News. Still, "I like the bug that he put in the first time 23 years ago. It was really cute." There are other clues that Guilbeau is the artist. The sculpture on Coughlin's lawn contains newspaper plates from a 1984 Lafayette, La., newspaper. Guilbeau's website says he was born in Lafayette in 1960. Messages left for Guilbeau were not returned. The postmark on the pictures was from Abita Springs, La., while the return address was from Covington, La.; 9News reported that Guilbeau has a post office box in Abita Springs, though Guilbeau's website lists his residence as North Carolina. Sackheim has an indirect connection to Guilbeau. He posted photos of the 1987 sculpture on the Boulder Facebook page that he moderates. Sackheim also tried to message Guilbeau on Facebook. Once Upton and Sackheim spent some time with their respective pieces, they each realized that they contained hidden messages. "The way it was written reminded me of the encrypted school girl notes I'd pass around to my friends in ... school," Upton wrote on the Phantom Sculptor Facebook page. Upton found mirror images that read in part: "PS 1-5-2011" "Junk only exists in the mind," "Discarded objects" and "Post consumerism." Sackheim's piece contained mirror images spelling out "PS: 1-5-2011," "Disposable Culture," "Fundament Capitalism" and "Greed = Generosity." Neither Upton nor Sackheim returned phone calls from AOL News. Still another unknown surrounds the artwork: What will happen to the piece that had been placed in front of the museum? It stood for only a week before six city workers dismantled it and moved it into storage. Police tried without success to contact Guilbeau, not because they view the guerrilla art as criminal, but because they wanted to know what to do with it. At this point, it is being considered a donation, and the Arts Commission will decide what to do with it, Boulder spokeswoman Sarah Huntley said. She did not know the estimated value of the piece. The note and earrings from it are on display at the museum. While Boulder would encourage artists to donate their work via a more traditional route, "The community has made it very clear that they are delighted by these gifts," Huntley said. Coughlin has decided that after a month, the sculpture is hers to keep, though she would like to have it moved to her back yard. As for others involved, they are just enjoying the intrigue. "Artist person totally has my heart!" Upton wrote.