Man accused in case of poison-laced letters has history of legal and other troubles "I know Kevin, I know his family," McCoy said, according to the Associated Press. Others who've known Curtis were less surprised, however, saying that his long, detailed Internet diatribes and erratic behavior were the signs of a mental illness that he has struggled with for years, one that left him at times delusional, narcissistic, paranoid and dangerously unpredictable when he was not taking his medication. "When he's on his medication, he is delightful, charming, likable," said Jim Waide, a family acquaintance who briefly represented Curtis in a lawsuit a decade ago. Curtis's father, Jack Curtis, 74, said that his son "does have some bipolar issues, but he don't have a violent streak in him whatsoever. That's why it's so hard for us to believe he put ricin in a letter to anybody, let alone the president. "He didn't put no ricin in it, hell, he wouldn't know where to get it," said the elder Curtis, adding that his son does write to lawmakers and inherited his father's outspoken streak. Curtis allegedly mailed three identical letters laced with the poison ricin on April 8 to the White House, the office of Sen. Roger Wicker (R-Miss.) and a local judge in Tupelo who had once handled an assault case against Curtis. The letters alluded to Curtis's novel-in-progress, called "Missing Pieces," in which he sought to espouse his long-held conspiracy theory about underground trafficking in human body parts. "No one wanted to listen to me before," read the letters, according to an FBI affidavit. "There are still "Missing Pieces" Maybe I have your attention now Even if that means someone must die. . . . In an online profile, Curtis called himself a "Father/Activist/Singer/Songwriter/Business Owner/Rebel." He described working as a celebrity impersonator along the Mississippi-Tennessee border, often performing as Elvis Presley. "He was quite entertaining," Wicker said Thursday, recounting the time a decade ago he hired Curtis to perform as Elvis at an engagement party. My impression is that since that time, he's had mental issues and perhaps is not as stable as he was back then. Court records show that Curtis has been arrested four times since 2000 in Prentiss County, where he lived most of the past two decades, and where charges against him have included cyber-harassment.