Jeremiah Lee Wright, 30, waived his right to an attorney and confessed to killing Jori Lirette within 30 minutes of being brought to the police station Sunday, Police Chief Scott Silverii said. He said Wright was booked with first-degree murder and held in lieu of $5 million bond.

He was in isolation, Silverii said during a Monday afternoon news conference. The department spokesman, Detective Ricky Ross, said he does not believe Wright has an attorney.

Flowers, balloons and stuffed animals were left Monday outside the house where Jori died.

``He was maybe the best thing that ever happened to me,'' his mother, Jesslyn Lirette, said at the news conference.

A preliminary autopsy found the boy was bludgeoned, decapitated and dismembered, Silverii said. Whatever hit him caused ``excessive bleeding in the head,'' he said.

Silverii said the motive was unclear, though Wright told police ``that he'd gotten to the point where he was tired of taking care'' of the boy, who had cerebral palsy and heart problems, needed a feeding tube, had limited speech and was in a wheelchair.

``He said when he put his head out by the side of the road it was so the mother would see it when she came by,'' Silverii said. He said Wright's only explanation for doing so was ``just that he wanted her to feel stupid when she saw the head.''

The police chief said Jori's feet and one hand also were cut off, recovered with the body in several white plastic garbage bags.

The slaying was the first in Thibodaux since 2008.

Silverii said the boy apparently was decapitated over the kitchen sink, which was sent to the Louisiana State Police crime lab along with a box of tools found nearby. Wright told investigators he began killing the boy about 30 minutes after Lirette had left Sunday to repair her pickup truck so she could take Jori to a doctor on Tuesday.

Police had been called to the house last month when the couple had an argument _ possibly about money _ though neither person brought charges, Ross said. The police chief said Wright had been arrested a few times previously, though he was never charged with violent crimes. Wright served 10 days for theft in 2005.

Lirette, 27, told The Daily Comet of Thibodaux that she and Wright had been together for 10 years, but that she had planned for some time to leave him.

She said she cared for another disabled person to pay household bills and was still around to care for her son, who had been born three months premature, could say only a few words and weighed no more than 50 pounds (22 kilograms) when he died.

``He was my star. No matter what people think or say, he was always top priority in my life,'' Lirette said through tears during the news conference. ``I've done everything I can for him.''