POPLAR BLUFF, Mo. (AP) _ Police running an undercover sting fed radio stations and a newspaper a false story, saying a lawyer had been castrated on Halloween during an attack at his home.

After the story made the front page of the Daily American Republic and was broadcast across southeast Missouri and northeast Arkansas, police revealed the assault was a hoax.

The sting was intended to convince a man who allegedly paid a police informant $4,000 for the job that the Arkansas lawyer really had been castrated and his arms and legs broken, police said.

On Halloween night, officers acted out the assault at the lawyer's home, and rushed a phony injured man to the hospital. When reporters heard on police scanners what they thought was a story, they contacted the sheriff's office in Clay County, Ark.

Sheriff Darvin Stow then told reporters that city attorney C.W. Knauts, of Piggott, Ark., was stabbed and rushed to a hospital. Stow said the attorney had two broken arms and was bleeding from the groin.

The target of the sting, Harold Speer of Greenway, Ark., was charged Thursday in Stoddard County, Mo., with conspiracy, burglary and assault. He was arrested in Arkansas. Knauts represented Speer's former wife in a 1985 divorce.

Investigators said they wanted to keep the plan a secret for a few days rather than arresting Speer on the spot when he hired the informant because Speer allegedly told the bogus hit man of other jobs he wanted done.

Authorities also said they hoped Speer might provide information on the slaying of his ex-wife in Phoenix a month after their divorce.

Stow said he was sorry if anyone was offended, but it was necessary.

''It's pretty disturbing to me,'' Stan Berry, news editor of the Daily American Republic, said Monday. ''We're not in the business of printing fake stories for anybody.''

The false information was given only by the Clay County Arkansas Sheriff's Department. No news conference was held and no press releases were issued by either the Missouri Highway Patrol or Arkansas State Police, although both were involved in the staged assault.