COLUMBUS, Ohio - A Columbus Public Schools teacher was charged this week for attempting to have sex with a teenage boy.

Mark Boster, who has been with the district for more than 20 years, was met on the city's west side by sheriff's investigators, 10TV's Patrick Bell reported.

Boster, 46, was charged with unlawful sexual conduct with a minor and importuning.

Detectives said that Boster made a full confession and was cooperating with authorities.

"I think it's hideous," said Franklin County Chief Deputy Steve Martin.  "This is a school teacher who's been in the system, at least in Columbus schools, for 23 years.  And yet, he's out there doing that."

Boster caught the attention of authorities in April, when a detective logged onto a chat room posing as a child.

"Mr. Boster thought he was talking with a 14-year-old boy, to have oral sex with him," Martin said.  "That's the reason he came to the prearranged location because that's who he thought he was going to meet."

According to Boster's personnel file obtained by 10 Investigates, the principal of Avondale Elementary School reported Boster was seen going into the restroom to watch boys urinate in 2003.

The principal also wrote, in a letter to the district's teachers, that Boster was investigated by Franklin County Children Services, and cleared, after grabbing a boy's breast and twisting it.

Also in 2003, a teacher witnessed Boster talking with a male student, putting the young man's knees between his knees and then rubbing his legs and upper thigh.

In 2004, Boster was reprimanded for making physical contact with a student in an inappropriate manner and was subsequently ordered to participate in an employee assistance program.

Boster was never fired.  Since January, he was worked at a Columbus Public Schools distribution facility after being diagnosed with health problems.  A district spokesman said that was unrelated to his current case.

On Friday, Boster lost custody of his 13-year-old son. The boy will remain in the care of children's services while investigators continue looking into the case against Boster.

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