NORTHAMPTON — A state appeals court has upheld the 2020 attempted murder conviction of Christopher Conley in a long-running case over the poisoning of his 7-year-old daughter.

The Massachusetts Appeals Court’s decision Wednesday ends a case that began in April 2015, after the child was admitted to Yale New Haven Hospital in Connecticut with life-threatening abdominal injuries. Conley, of Northampton, was charged with attempted murder after he admitted injecting a caustic substance into the girl’s abdomen in an attempt to kill her, then giving her a heavy dose of opioids to “put her to sleep.”

At his Hampshire Superior Court trial in 2020, Conley claimed that his confession was a lie. The jury found him guilty of attempted murder, assault and battery on a child by means of a dangerous weapon (opioids) and assault and battery on a child causing substantial bodily injury.

Judge Richard Carey sentenced Conley to 16-18 years in prison. The case was prosecuted by Assistant District Attorney Linda Pisano and First Assistant District Attorney Steven E. Gagne.

Following his conviction, Conley filed a motion seeking a new trial, arguing that Carey erred in allowing jurors to hear that he had previously poisoned the child when they lived in Boston, and in excluding evidence about a conversation he had with his attorney in which he disavowed his confession. The appeal also cited inadequate defense representation. Carey denied that motion in November 2021.

Conley appealed that decision to the Massachusetts Appeals Court, which heard the case on July 6, 2023, in oral arguments presented by Northwestern Assistant District Attorney Bethany Lynch. In a 37-page decision released Wednesday, the court upheld Carey’s denial of the motion for new trial and affirmed Conley’s convictions.

“We have carefully reviewed each of the defendant’s arguments and the judge’s careful resolution of them. No purpose would be served by repeating the judge’s analysis. There was no abuse of discretion,” the appeals court wrote.

In June 2021, the child’s mother, Julie Gordon, formerly Julie Conley, was convicted of a misdemeanor charge of reckless endangerment of a child and placed on probation until September 2023, the DA’s office reported. That charge stemmed from Gordon’s reporting of false or exaggerated symptoms supposedly experienced by her daughter, which led to a series of unnecessary and dangerous medical procedures.

Neither Conley nor Gordon has custody of the child, according to the DA’s office.