Atlanta ? The FBI will lead an investigation into the fatal shooting of an 88-year-old woman during a drug raid last week.

Three plainsclothes officers were wounded when they entered Kathryn Johnston’s home looking for cocaine based on tips from an informant.

Police said the informant told officers he had purchased drugs in the home earlier, prompting investigators to get a warrant. But Atlanta Police Chief Richard Pennington said it was unclear whether there had been a drug deal or whether the suspected drug dealer actually exists.

Monday evening, WAGA-TV aired an interview with a man who said that he was the informant, and that he had never purchased drugs at Kathryn Johnston’s home. The man, whose identity was obscured by the TV station, also said that police had asked him to lie about providing the information, but that that was before he knew the elderly woman had been killed in a shootout there.