DUBLIN — A Dublin jury found two 14-year-old boys guilty on Tuesday in the killing of a teenage girl last year, the youngest people ever to be convicted of murder in Ireland.

In a case that has shocked and horrified the nation, the two boys, who were both 13 at the time of the killing, were found to have murdered Ana Kriegel, 14, whom they had lured to an abandoned house on the outskirts of the town of Lucan, a Dublin suburb.

Her naked body was found in the house three days after she had been reported missing, with over 50 separate injuries. A state pathologist testified that there was evidence of compression of her neck, but that the likely cause of death was blunt trauma to her head and neck, possibly from blows from a bloodied stick and concrete blocks found near her body.

One teenager, known as “Boy A” because of legal restrictions on reporting identities in underage cases, was convicted of murder and aggravated sexual assault after the police found his semen on clothes torn from the girl’s body. The victim’s blood was also found on his shoes and on items from what the police called a “murder kit” — kneepads, gloves, shin-pads, a scarf and a homemade horror mask found in a backpack in Boy A’s home.

The prosecution said that the other child, “Boy B,” lured Ana to the murder scene and watched the assault. Her father, who was home at the time, testified that Boy B had called at their house on the night of the murder, and that his daughter had gone out with him, promising not to be long, although they were not friends.

Boy B was convicted largely on the basis of admissions and lies he made to police interrogators, and closed circuit images and witness testimony from around the time of the attack.

The two boys will be sentenced on July 15. While life sentences are mandatory in Irish law for adults in cases of murder, juveniles are treated differently.

In preparation for the sentencing, the presiding judge, Paul McDermott, has asked for probation, psychiatric and school reports on the two boys, which will be used, along with character witnesses and statements from those close to the victim, as guidelines.

The circumstances of Ana Kriegel’s short life and brutal death have made the case particularly disturbing for a country with little experience of premeditated murder by teens.

Born in Siberia in 2004, she was adopted two years later from a Russian orphanage by Patric and Geraldine Kriegel, a retired French professor and his Irish-born wife, an employee of the Irish state railway network.

They brought her back to their home in Lucan, a pleasant suburb on the western edge of Dublin. They kept her original first name, Anastasia, and raised her to be aware of her Russian past and culture.

A tall, striking girl who excelled at swimming, modeled in a school fashion show and loved singing and dancing, Ana also encountered learning difficulties stemming from poor eyesight and a childhood tumor that left her virtually deaf in one ear.

Her parents, who attended every day of the trial in Dublin’s Central Criminal Court, said that while she craved friendship, she had few friends outside her family and had been ruthlessly bullied and sexually harassed for being different from others at her high school. She had started to self-harm, they said, and at one point was caught sending herself bullying messages from a fake social media account.

Despite her behavioral problems, she remained a fun-loving and lively child, and was close to her supportive parents and family. Her mother, returning from work on the evening of the girl’s death, immediately became alarmed when she learned that Ana had gone off alone with Boy B, who she knew was not a friend of her daughter.

Boy A later told the police that he had sent Boy B to fetch Ana because he knew that she was interested in him and wanted to tell her “gently” that he was not interested in her.

Shortly after the killing, which the police believe happened immediately after Ana entered the room in the abandoned farmhouse, Boy A was seen crossing a local park with injuries to his arm and leg and cuts to his face. Big for his age and with some martial arts training, he claimed to have been attacked by two men. The police believe that Ana inflicted the injuries as she fought desperately for her life.

Both boys were supported by parents and family during the four-week trial. The father of Boy B turned angrily on those in the court after the verdict, insulting them and sarcastically applauding the conviction of “an innocent boy.” Boy A’s parents wept and hugged their son before he was led away.

The last word in the case, until the sentencing next month, went to the victim’s parents, who spoke briefly with reporters outside the courthouse.

“Ana was a dream come true for us, and she always will be,” Geraldine Kriegel said. “She will stay in our hearts, forever loved and forever cherished. We love you, Ana.”