Spoiler alert! Following in the bloodied loafers of despised characters J.R. Ewing (Dallas) and Mr. Burns (The Simpsons), the villainous Paul Young (Mark Moses) will be shot by an unknown assailant in the final moments of Desperate Housewives' December 12 cliff-hanger. Fans will be left guessing whodunit until early next year. You may recall in the season premiere, Felicia (Harriet Sansom Harris) vowed from her prison cell that Paul, who'd murdered her sister Martha, would be dead within six months. Now that he's destroyed picturesque Wisteria Lane, everyone has a motive. "We very carefully planted guns in the episode," says exec producer Bob Daily, who narrows the suspect list to four.Bree (Marcia Cross), whom Daily calls "the most avid markswoman on the Lane," is enraged after Paul turns the property next door into a halfway house for paroled ex-cons. Lee (Kevin Rahm), Paul's realtor, will become the neighborhood outcast after inadvertently helping Paul transform the hood. "As Lee and Bob are packing to leave the lane," says Daily, "we see Lee's packed a gun." Beth (Emily Bergl), Felicia's daughter and Paul's wife, already pulled a weapon on Susan a few weeks back.But the most likely scenario is that Felicia was the "puppet master" who hired someone to do the deed. Maybe MIA Mike Delfino (James Denton), who is desperate for dough and has a grudge against Paul, or my other guess, Paul's long-gone son, Zach (Cody Kasch), who despises his dad perhaps more than anyone. "Interesting guess," says Daily, who guarantees that the shooter "is someone who has been a regular character on the show."Subscribe to TV Guide Magazine now!