Editor's Note: This story has been edited since its original version.

BEDMINSTER, N.J. — Stephen Bradley Mell had a $3.8 million home, a brokerage firm, two airplanes, a helicopter, a wife and three children.

On Tuesday, he will have possibly five years in federal prison and five years of supervised release after pleading guilty in late 2018 to charges of interstate travel to engage in illicit sexual conduct and receiving child pornography.

Mell is also facing the possibility of a multi-year sentence in state prison after pleading guilty in May to engaging in sexual relations with a female victim under the age of 16 in New Jersey

Known by many as Brad, Mell was an active community member, serving on a school's board and volunteering for charities. But it was his love of flying that contributed to his life going into a tailspin, law-enforcement authorities say.

A 2018 federal complaint graphically details the charges: Mell began communicating with the 15-year-old through text messages and SnapChat in 2017. He was 51 at the time.

Mell already had “a pre-existing relationship with the minor” when he began communicating with her, according to the brief filed in support of his release on bail.

“In fact, it was the minor’s mother who first introduced Mr. Mell to obtain flight lessons for the minor,” the brief states.

Communication between Mell and the minor became sexual when Mell asked the girl “if she knew how to perform oral sex.” He later invited her to spend time alone with him at his Bedminster home.

On June 20, 2017, Mell “performed oral sex acts” on the girl, according to the complaint. Two weeks later, he messaged the girl and told her, “Miss you so much.”

On July 5, 2017, he again performed sex acts on the minor, according to the complaint. One day later, he purchased an emergency contraceptive pill for her.

“If you are nervous it will hurt more,” Mell said to the girl in a text message. “When you are turned on is when it will feel ok.”

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On July 20, 2017, Mell flew with her in his private plane from Somerset Airport to Barnstable, Massachusetts, on Cape Cod “for the purpose of engaging in illicit conduct, specifically, a sexual act with a person under the age of eighteen."

On the flight back, Mell put the aircraft in autopilot mode and engaged in sex acts, the complaint says.

The next day, Mell performed sex acts on the minor in Hunterdon County, according to the complaint.

Throughout August 2017, Mell asked the girl to send him text messages, SnapChat photos or FaceTime video chats of images of the minor engaged in sexually explicit conduct.

Sometime during the summer of 2017, Mell gave the girl a birthday card for her 16th birthday.

On Aug. 23, 2017, Mell arranged for a hotel room to be booked on the same day and in the same town the minor was out eating dinner.

“Now let me get a room and we are all set,” Mell said to the girl in a text message.

Around that same time, Mell and the minor traveled to New York City separately and, while in the city, engaged in sexual intercourse, according to the complaint.

He then took a photo of the girl with his cellphone while she was standing naked in front of him, her “genital area clearly visible.”

On Sept. 18, 2017 he begged the minor to get birth control.

“Please get the IUD,” he texted her. “I know you are trying.”

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In October, about six months after the two began communicating, Mell sent the minor a text message that read: “Trust me the sex is amazing but so is being around you.”

The last event chronicled in the federal complaint took place on Nov. 14, 2017, when Mell requested the girl to “Send me a nice naked pic cute thing.”

Court documents also show that his wife has filed for divorce.

On Tuesday, Mell will appear in federal court to find out what his sentence will be.

Mell's lawyer, Robert Bianchi, declined to comment on the case.

Mell, how 53, lived in a 7,768-square-foot home on Black River Road in the northwestern corner of Bedminster.

After earning a master’s degree in psychology, he worked as a trader for State Street Bank in Boston where he "began to develop a talent for finance," according to a legal brief filed May 5, 2018, in federal court to support his release on bail.

After marrying, he moved back to New Jersey and began working as a municipal bond trader at his father's company, W.H. Mell Associates.

He was coach of the hockey team for more than a decade at the Essex Hunt Club in Peapack-Gladstone, an organization better known for its fox hunts.

Mell also served as a board member at Westminster School, a prep school in Connecticut, where his son is a student. In May 2017, he received the "Unsung Hero Award" from Far Hills Country Day School.

Mell became passionate about flying as a teen. He earned his pilot's license at the age of 16.

"His love of flying, along with the peace, serenity and joy he got from being in the air, became the source of his greatest memories," according to the brief.

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