(CBS/AP) OZARK, Miss. - Authorities in Mississippi say they are searching for Everett Dutschke, the chief person of interest in the investigation into poisoned letters sent to President Barack Obama and other officials.
Itawamba County Sheriff Chris Dickinson says he is helping the FBI search for Dutschke. The federal agency told him that Dutschke had been under surveillance but slipped away on Wednesday.
No charges have been filed against Dutschke.
Itawamba deputies searched a home in Ozark where Dickinson said Dutschke was believed to have been on Wednesday, but found no one.
The sheriff says he believes a friend of Dutschke "may be helping him to lay low."
FBI spokeswoman Deborah Madden would not comment on the search.
Dutschke did not answer his cellphone when The Associated Press tried to contact him on Thursday.
Only one of three ricin-laced letters mailed this month to public officials made it into the hands of an intended target - the letter meant for for an 80-year-old Mississippi judge named Sadie Holland.
Investigators are working to piece together what motivated someone to send the letters to her, the President and U.S. Sen. Roger Wicker (R-Miss.). Holland is a common link between two men who have been investigated in the case.
Holland presided over a 2004 assault case against Paul Kevin Curtis, 45, an entertainer who had been the top suspect in the case until prosecutors dropped charges against him Tuesday.
And Holland's family has reportedly had political skirmishes with Dutschke, whose home and former place of business have been the subject of searches by investigators for two days this week.
Steve Holland, Sadie's son, said he believes his mother's only encounter with Dutschke was at a 2007 rally in the town of Verona. Running as a Republican, Dutschke lost a lopsided election to Steve Holland that year.
He said his mother called out Dutschke after he made a derogatory speech about the Holland family.
"She just got up and said 'Sir, you will apologize. This is where I was born in Verona and we've been here five generations and you will apologize.'"
Steve Holland said Dutschke altered a photo to make him look like the fictional Boss Hogg from the "Dukes of Hazzard" TV series, portraying Holland in a white suit and hat with a big cigar.
"He'd just go off on a tangent about Boss Holland is a thief and Boss Holland has been stealing from you people and Boss Holland this and Boss Holland that," Holland said.
Dutschke told the AP on Tuesday that he has no problem with Sadie Holland. "Everybody loves Sadie, including me," he said.
Sadie Holland declined to talk with the AP.
On Wednesday, dozens of investigators were searching at a small retail space where neighboring business owners said Dutschke used to operate a martial arts studio. Officers at the scene wouldn't comment on what they were doing.
Investigators in gas masks, gloves and plastic suits emerged from the business carrying five-gallon buckets full of items covered in large plastic bags. Once outside, others started spraying their protective suits with some sort of mist.
Dutschke was seen outside the studio observing the search.
Dutschke's attorney, Lori Nail Basham, said Dutschke is "cooperating fully" with investigators and that no arrest warrant had been issued.
Federal authorities have not said what led them to drop the charges against Curtis, the initial suspect in the case, and his lawyers say they're not sure what new evidence the FBI has found.
Curtis, who performs as Elvis and other celebrities, describes a bizarre, years-long feud with Dutschke, who insists he had nothing to do with the letters.
The two worked together at Curtis' brother's insurance office years ago, Curtis said. He said Dutschke told him he owned a newspaper and showed interest in publishing his book called "Missing Pieces," about what Curtis considers an underground market to sell body parts.
But Dutschke decided not to publish the material, Curtis said, and later began stalking him on the Internet.
For his part, Dutschke said he didn't even know Curtis that well.