"There is a value to a sure guilty plea because letting him [Epstein] walk, letting what the state attorney was ready to do go forward, would have been absolutely awful," Acosta said at a press briefing on Wednesday.
Acosta explained the goal was to put Epstein behind bars, ensure he registers as a sex offender, provide his victims with the means to seek restitution and protect the public by putting them on notice that a sexual offender was in their midst.
"He's a bad man and he needs to be put away," Acosta said.
On Tuesday, House of Representatives Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer as well as several Democratic presidential candidates called on Acosta to resign in connection with his role in the Epstein plea deal that has been criticized as too lenient.
US authorities on Monday formally charged Epstein with sex trafficking and conspiracy after he allegedly abused dozens of underage girls more than a decade ago.
Epstein was previously targeted by an investigation in 2005 over allegations that he solicited sexual services from girls as young as 14 or 15 years, and allegedly loaned the girls to other people for sexual exploits.
However, Epstein reached a plea deal with prosecutors by pleading guilty to charges of soliciting prostitution and serving 13 months in prison.
As a US attorney in Florida, Acosta decided at the time not to prosecute Epstein on federal sex trafficking charges, but agreed to the lesser counts.
Vice President Mike Pence told reporters later in the day that the White House welcomes Acosta’s explanation and were pleased that he came forward to explain the basis of the 2008 plea agreement.