Former computer analyst Craig R. Sadosky has pleaded guilty to killing 3-year-old Andrew Slyter four years ago in Old Lyme and will be sentenced June 29 to 40 years in prison.

Sadosky, who had been charged with capital felony and first-degree sexual assault, accepted a plea offer from the state after years of negotiations between his attorneys and the state. Since there is no parole for convicted murderers, he will be required to serve every day of his 40-year sentence. A tall, broad man in an orange prison jumpsuit, Sadosky stood between his attorneys, Fred DeCaprio and Kevin Barrs, and calmly answered a series of questions to indicate he understands the plea deal. Two correction officers who accompanied him to court because of the severity of the charges stood behind him.

Sadosky told authorities he had awakened with Andrew on the morning of Nov. 19, 2007 and taken him outside his home at 67 Hillcrest Road to see the sunrise, according to prosecutor Lawrence J. Tytla. He said he became frustrated with the child while they were walking, picked him up and threw him down an embankment. The child started crying, and Sadosky said he punched him, kicked him and threw him down once again, Tytla said. Sadosky said Andrew was unconscious and he dropped him again. He said returned to the house with Andrew and took him to the bathroom to clean him up.

Tytla said that only Sadosky knows what actually happened that night. Andrew Slyter suffered extensive trauma of the head, neck, chest, abdomen and groin. The state Office of the Chief Medical Examiner ruled that he had died of blunt head trauma.

The child's maternal grandparents, who had met with the prosecutor and victim advocate before Sadosky was brought into the courtroom, listened to the proceeding with haunted expressions on their faces. They elected not to speak today but indicated they may be heard at the sentencing.

"It's fair to say they're not happy with this disposition," Tytla said.

Andrew's paternal grandparents had also hoped for a sentence that would assure Sadosky would remain in prison for the remainder of his natural life, Tytla said. Tytla said he recommended the 40-year sentence because he thinks it is appropriate, given the circumstances of the crime.

Sadosky pleaded guilty under the Alford Doctrine, which indicates he does not agree with the state's allegations but does not want to risk conviction and the possibility of a harsher sentence at trial. His attorney, DeCaprio, said Sadosky is using the Alford plea because he disputes the state's allegation that he killed Andrew intentionally.

Sadosky has been held in prison in lieu of $2.5 million since the crime. Doctors immediately became suspicious when Sadosky and the boy's mother, Sarah Slyter, took Andrew to a clinic in Essex, unresponsive, cold and wrapped in a blanket. The couple told doctors Andrew had fallen on the lip of the driveway, but the extent of the boy's injuries was inconsistent with that story. Andrew was flown to Yale-New Haven Hospital's trauma center, where he was pronounced dead. Sadosky provided police with a lengthy statement about the incident.

Sarah Slyter told authorities she woke up around 3:30 a.m. and heard Sadosky "cleaning rooms in the house." She woke up again at 7:30 a.m. and found Sadosky in the bathroom with her son, whose skin was blue.