An Ohio pedophile used a slick trick to get inside a locked bathroom stall and assault a 6-year-old Girl Scout waiting for her mom, said prosecutors.

Robert Kevin DeWeese, 37, was charged with two counts of gross sexual imposition, two counts of rape, and single counts of abduction and kidnapping, according to an indictment in Warren County Common Pleas Court, reports Fox 19.

The creepy crime occurred on Feb. 6 inside the bathroom of a Five Below store in South Lebanon, Ohio — just three days after DeWeese was released from a 3-year prison sentence for a parole violation tied to another child sex crime in 2021, said prosecutors.

The mother and daughter were in the store when the girl soiled her pants. They went into the bathroom, where the mom locked her daughter in the stall.

“She told the daughter that she was going to go [out into the store to] get those pants and leave the door locked until she heard the special knock and she described to the girl what the special knock was going to be,” wrote Warren County Prosecutor David P. Fornshell in a social media post.

“Deweese reportedly eavesdropped on this conversation, used the special knock to gain access to the bathroom and sexually assaulted the girl.”

The girl screamed as loud as she could, using the “lion’s roar,” a technique she’d learned in Girl Scouts. This startled Deweese and he fled, said Fornshell.

Her mother immediately dialed 911.

Warren County Sheriff’s deputies tracked Deweese to a relative’s home about a mile away, arrested him and took him to the Warren County jail with a cash-only bond set at $702,500.

He was indicted on multiple charges, including rape of a child.

At Deweese’s March 4 arraignment, he was designated a “sexually violent predator.” Bond was set at $1 million.

The perv’s record goes back 20 years, starting with a sex charge conviction at age 18, including an October 2021 conviction in Fairfield County for rape of a child younger than 13.

“Someone like this should remain permanently separated from society,” said Fornshell. “Obviously, our hope is that he’ll go to prison for a long time.”

The perv’s record goes back 20 years, starting with a sex charge conviction at age 18, including an October 2021 conviction in Fairfield County for rape of a child younger than 13.

Deweese remains in the Warren County Jail. His next court date is March 19, according to cops.