FORT LAUDERDALE, Fla. (AP) — Keep him talking, don’t interrupt him and, no matter what, don’t ask why he killed his victims.

Those were the instructions Texas Ranger James Holland gave to the dozens of homicide detectives around the country when they got their moment with Samuel Little, hoping to solve decades-old cold cases and bring back answers to desperate families from the man the FBI identified this month as the most prolific serial killer in U.S. history.

Little ultimately spilled forth with chilling confessions, claiming he killed 93 women in all between 1970 and 2005 and smilingly recounting the details with startling clarity. But to get what they needed, detectives had to employ a certain amount of psychology, some of which made them uncomfortable, such as laughing along with him or putting up with his flirting.

Miami-Dade Police homicide detective David Denmark and his partner interviewed Little last October about two murders in the Miami area from the 1970s. Holland had told them what to expect.

“You have to change your attitude and you have to become his friend,” Denmark said. “And you have to laugh with him and make fun of his victims sometimes, sort of like, ‘Yeah, I guess at that point she deserved it.’ Even though you hate saying it. You want him to think, ‘These guys are pretty cool’ to keep him talking.”

For Denmark, Little recalled his first victim, 33-year-old Mary Brosley, saying that he would never again try to bury a body in Florida’s hard limestone soil and that he had to leave part of her leg exposed. He also confessed to killing 25-year-old Angela Chapman in 1976, saying he started to drown her, then pulled her out of the water and strangled her.

He remembered Brosley’s flowered sundress and how he played with her chain necklace and marveled at her beautiful neck before strangling her.

Brosley’s sister Clare Coppolino said she had no idea her sister had moved to Florida, describing it as “an absolute shock” when she heard from the detective after nearly 50 years. She said her initial reaction to Little’s crime was “anger, but then more pity for him than anything. Pity to think, ‘I don’t know what his background was,’ but to think this man ended up murdering all these women.”

Little, 79, is now serving multiple life sentences for three killings in California. He also pleaded guilty to a 1994 murder in Odessa, Texas. Holland elicited scores of confessions from him last year in Texas and then set the guidelines for detectives who would later arrive in the state one by one with stacks of old case files from California to Florida.