Adam Joseph Barney admitted 'lashing out ' at the baby girl because of his frustrations over the fact she would n't stop crying , the dirty living conditions and her siblings misbehaving . A man has admitted killing his girlfriend 's 14-month-old baby daughter by punching her with 'everything he had ' in the head and stomach . Adam Joseph Barney told investigators he was caring for Kenzie Rose La Buy when he became frustrated that she would n't stop crying . The 24-year-old was living with his girlfriend and her children at the Western Colony Inn in Ogden , Utah , at the time of the incident in late August last year , according to Deseret News . He had been looking after the the baby girl while her mother was at work when he lost his temper and repeatedly punched her . Barney gave the attack 'everything he had ' , he reportedly told detectives who testified in the case , but also claimed he did not kill her on purpose . According to the prosecution 's case 'Barney admitted that due to his increased frustration over the dirty living conditions , the victim crying and other two children misbehaving , he lashed out at ( the girl ) . ' He reportedly left Kenzie lying on a bed while he cleaned up , then when he placed her in a buggy he noticed she seemed lethargic and was having trouble breathing . An autopsy concluded Kenzie died of blunt force trauma to the abdomen . She had for some time before Barney called 911 . He pleaded guilty in 2nd District Court on Wednesday to aggravated murder , a first-degree crime . In exchange for the plea , prosecutors will not seek the death penalty and will recommend a sentence of 25 years to life with a possibility of parole , according to court documents . Barney will be sentenced on May 13 . Kenzie 's father , James La Buy , told reporters at a hearing last month that he would prefer to see Barney behind bars than on death row . ' I think ( the death penalty ) is an easy way out , to tell you the truth , ' he said .
Adam Joseph Barney was caring for Kenzie Rose La Buy in Ogden , Utah . Lost his temper with youngster and punched her with 'everything he had ' Noticed she was struggling to breath but did not call 911 until some time after she had died from District Court to the abdomen , autopsy found . 24-year-old was also watching girlfriend 's two other children at motel .