Joran van der Sloot Update: FBI Official Responds to Blackmail Sting Criticism

NEW YORK (CBS) The FBI is defending its failure to arrest murder suspect Joran van der Sloot on extortion charges in the Natalee Holloway case, saying they were getting closer to making a murder arrest in that case, and didn't want to blow the investigation.

PICTURES: Joran van der Sloot
PICTURES: Stephany Flores

The Bureau is coming under some fire for not arresting van der Sloot in Aruba, since he then allegedly then took the money from the exortion sting and went to Peru, where he has since been jailed in the killing of 21-year-old Stephany Flores, who was murdered the last week of May.

A senior FBI official tells CBS News that the Dutchman "had avoided arrest for five years. If we had nabbed him [for extortion], he would have clammed up. He is not afraid of anyone. It would have spooked him."

According to the official, the FBI felt that for the first time in five years they were on the brink of finding Natalee Holloway's body. The FBI says it was receiving statements from van der Sloot about how and where he hid the body. Aruban officials, along with FBI agents, "were working this very intensely," including looking at blueprints, making plans to dig and bring in cadaver dogs.

"We were not trying to build a white collar extortion case. We were trying to solve the crime," the senior official told CBS News.

The official said there was no evidence van der Sloot, now 22, was a serial killer or about to commit another crime. The Bureau believed he was desperate for money and thought he would use it to feed a gambling addiction.

The FBI official adds that the Arubans couldn't stop him from leaving the country, and neither could the FBI because "it's not our country and he isn't a US citizen."

"We believe it was a very logical investigation," the senior official told CBS News.

The FBI says on Ma y 10, a $15,000 wire payment was sent van der Sloot with money from the Holloway family, which established the crime of extortion. There was also a 10-thousand dollar cash payment, which the Bureau says couldn't be used as a basis for a criminal charge.

The extortion charges against van der Sloot in the Holloway case were announced Thursday, June 3, the same day he was captured in Chile in the murder of Stephany Flores in Lima, Peru.

Natalee Holloway disappeared five years ago in Aruba, during the Alabama teen's senior class high school graduation trip.

Complete Coverage of Joran van der Sloot on Crimesider