Two years after a New London jury convicted Edward J. Allen of sexually assaulting a young girl who lived in his Groton home, the 67-year-old retired welder turned himself in today to begin serving a 13-year prison sentence.

Allen had remained free on a $250,000 bond while appealing his April 2011 conviction on three counts of first-degree sexual assault and three counts of risk of injury to a minor.

The state Appellate Court had upheld the conviction in January 2013. Edward then appealed to the state Supreme Court, which denied his request to hear the case.

Allen this morning met his attorney at the same courthouse where his trial had taken place and turned himself over to begin serving his sentence of 18 years in prison, suspended after 13 years served, followed by three years of probation. He will be required to register as a sexual offender for the rest of his life.

According to testimony at the trial, Allen had performed deviant sexual acts on the victim when she was between 7 and 11 years old. The victim, who then moved out of sate, disclosed the sexual assaults six years later when her mother told her that Allen, who had taken in the family during a difficult time in 2000, was coming to visit.

The ensuing investigation led town police to another witness, a 27-year-old who had lived in the same Groton neighborhood. Allen was not charged in connection with the second woman’s complaint, because the statute of limitations had expired.

The victims didn’t know each other, but both were familiar with the pornographic videos and devices in Allen’s bedroom, and both were willing to describe them in detail in open court when called to the witness stand by prosecutors David J. Smith and Christa L. Baker.

Part of Allen’s appeal involved Judge Stuart M. Schimelman’s decision to allow the jury to hear about Allen’s so-called “uncharged prior misconduct” based on the similarities of the cases. At the trial, he had instructed the panel that the purpose of the second woman’s testimony was limited and that Allen was on trial only for acts involving the teenage victim.

The Appellate court found that the judge properly admitted the evidence of Allen’s uncharged sexual misconduct. Allen had also appealed the judge’s decision to keep from his defense team the victim’s counseling records. The appeals court ruled that Schimelman, who had reviewed the records in private before issuing the decision, had not abused his authority. The court also ruled that Allen could not prevail on his claim that there was insufficient evidence to convict him.