LITTLE ROCK (AP) — A teenager accsed of killing a Hensley man and his 1-year-old daughter in 2009 pleaded guilty Thursday as part of a deal with Pulaski County prosecutors.

Daniel Gatrell pleaded guilty to first-degree murder in the death of Hannah Dowdie-Palmer and to first-degree manslaughter in the death of Michael Palmer during a court hearing. Gatrell, 17, is to be sentenced to 40 years in prison on the murder charge and 10 years on the manslaughter count, authorities said.

The sentences are to run concurrently. He will be eligible for parole in about 28 years.

Prosecutors charged him and his cousin, Robert Gatrell, with capital murder for the Dec. 12, 2009, deaths in Sweet Home. Daniel Gatrell's attorneys had sought to have him tried as an adult, but that proceeding was postponed last month. He pleaded guilty as an adult.

According to investigators, the Gatrells killed Michael Palmer then put him inside his pickup truck and set it on fire with him and Hannah inside. Palmer and his child were burned beyond recognition.

Daniel Gatrell declined the plea deal earlier Thursday.

"We just weren't ready this morning and thought about it over lunch and this early afternoon and he just decided that's what he wanted to do," his attorney, Hubert Alexander, told KLRT-TV.

The plea deal requires Daniel Gatrell to testify against his cousin, Robert.

"I can't comment directly on the facts of the case but it's always good to have as many witnesses to a crime as there are," prosecutor John Johnson said.

Alexander said when his client takes the stand, he'll do what he did Thursday.

"He's just going tell the truth. Just like he said he'd do today," Alexander said. "He'll just testify truthfully."