NEW YORK - A white man accused of stabbing a black man to death in a random racist attack told authorities he'd made a mess during the killing and they'd done a "terrible job" looking for him, according to court papers filed Thursday.

"I guess you're going to want to take my shirt and pants ... I made a mess," James Harris Jackson said, according to court papers. "I really butchered him."

Jackson, 28, has been charged with murder as a hate crime in the death of Timothy Caughman. His lawyer Patrick Brackley asked a judge to suppress the statements because he hadn't been properly read his rights.

Brackley also said he needed more time to determine whether to argue an insanity defence because his investigators were poring over information and laboriously seeking background on Jackson.

Authorities say Jackson admitted killing the 66-year-old Caughman at random on March 20 as part of a plan to kill black men in New York City. He pleaded not guilty to murder as a hate crime and murder as an act of terrorism.

Jackson is from Baltimore and a veteran who served in Afghanistan. Family friends say the allegations are out of line with how he was raised, in a tolerant and liberal middle-class family.

"You need to arrest me. I got the knife in the coat," Jackson said to police, according to papers. "You did a terrible job looking for me. No this isn't the knife, it's in a park."

He directed authorities to a garbage can in a park where they found the other knife, they said.

In a jailhouse interview with the Daily News of New York, Jackson said he intended the stabbing as "a practice run" in a mission to deter interracial relationships.

He said he would rather have killed "a young thug" or "a successful older black man with blondes ... people you see in Midtown. These younger guys that put white girls on the wrong path."

Caughman, who was remembered as a gentleman and a good neighbour, was alone and collecting bottles for recycling when he was attacked from behind with a sword. He staggered, bleeding, into a police station and later died at a hospital.

News from © The Associated Press, 2017