A convicted sex offender attended at least two Arizona middle schools, sat through seventh-grade courses and turned in homework as he moved around the state pretending to be 12 years old, officials say.

Authorities in Yavapai County have accused Neil Havens Rodreick II, who is really 29, of assaulting a girl. They are not releasing details.

Rodreick was arrested last week after spending a day at the Mingus Springs Charter School in Chino Valley, about 90 miles northwest of Phoenix. School officials there called police after they checked what they called a phony birth certificate and other admissions documents.

He has been charged with misdemeanor assault, conspiracy to commit fraud, conspiracy to commit forgery, failing to register as a sex offender, and possession of a forgery device. He remains in the Yavapai County jail.

The sheriff's office there said Rodreick conned two men he was living with and having sex with into believing he was a young boy. One of them, 61-year-old Lonnie Stiffler, called himself Rodreick's grandfather when he tried to enroll him at Mingus Springs as "Casey Price."

Officials at another school, in the Phoenix area, said they were reviewing their admissions policies to figure out how they could have let an adult sex offender mix with students for so long.

"Our first priority is to help our students and our families establish a sense of security on our campus," said Rhonda Cagle, spokeswoman for the Imagine School at Rosefield, a charter school for kindergartners through eighth-graders that Rodreick attended sporadically from August to November.

Rodreick showed up Aug. 14 at the Imagine School, officials said. He came to class from time to time, attending about 50 days until November, when administrators kicked him out for poor attendance.

"He was quiet," Cagle said of Rodreick. "He turned in his homework. There were no discipline issues. He was never sent to the principal's office. By most accounts he was aloof and kept to himself."

Police say Rodreick may also have tried to enroll in other Arizona schools.

Authorities say Stiffler and Robert James Snow, 43, met Rodreick online, thinking he was a pre-teen, took him from Oklahoma to Arizona and carried on a sexual relationship with him. They were arrested after authorities served a search warrant at their Chino Valley home Thursday along with Brian J. Nellis, 34, a friend who authorities say followed Rodreick from Oklahoma to Arizona.

The Yavapai County attorney's office said it charged all three, along with Rodreick, with conspiracy to commit fraud and conspiracy to commit forgery. Nellis and Snow were also charged with failing to register as sex offenders.

Because Snow and Stiffler are accused of thinking they were having sex with a minor, they were charged with attempted child molestation and attempted sexual contact with a minor.

All four men remain in jail. Yavapai County Attorney Sheila Polk would not comment Tuesday, and county public defender's office did not return phone calls.

Nellis' older brother, Richard, told The Associated Press that Rodreick met Brian Nellis more than 10 years ago while the two men were at Army basic training.

"When he got out of the military, he came back here and then left again to go to Fort Drum (New York)," said Richard Nellis, who lives in southwest Oregon. "The next thing we know he got out and is in Oklahoma with Neil, and that's when it started going downhill."

In 1996, police in Chickasha, Okla., arrested Rodreick after a 6-year-old boy said Rodreick spoke about "bad nasty things," documents say. Rodreick was convicted in 1996 of lewd and indecent proposal to a minor and sentenced to prison.

A year later, Nellis was convicted of lewd molestation and was imprisoned for three years, Oklahoma records say.