PORTLAND — A Lewiston man admitted Tuesday to having child pornography and exploiting a child sexually, both federal felonies.

Timothy Doyon, 28, appeared in U.S. District Court in handcuffs where he pleaded guilty to sexual exploitation of a child, a crime punishable by 25 to 50 years in prison.

He also pleaded guilty to possession of child pornography, which carries a minimum sentence of 10 years in prison and a maximum sentence of 20 years.

The penalties were enhanced because Doyon has a prior conviction for possessing child pornography.

On each count, he faces a fine of up to $250,000 and supervised release after prison for five years to life. Doyon waived his right Tuesday to have the charges presented to a federal grand jury for indictment.

Investigators said in court papers that, on or about Jan. 11, Doyon used and employed a minor to engage in sexually explicit conduct for the purpose of producing a visual depiction of that conduct.

On or about May 5, Doyon had a memory card that included images of child pornography, according to court papers.

“At least one image of child pornography involved in the offense involved a prepubescent minor or a minor who had not attained 12 years of age,” according to a charging document in court files.

On about July 21, 2016, Doyon was convicted of possession of sexually explicit material of a minor under 12 in Androscoggin County Superior Court, according to court records.

Doyon, who was arrested in August, is in federal custody, having waived his right to a hearing on his detention.

He may not withdraw his convictions, but may appeal if he is sentenced to more than 25 years in prison.

No sentencing date has been set.