Frantic banging summoned Nicholas Harsted to the front door early Wednesday, where a teenage neighbor stood panicked, red blisters spreading across his chest, the skin peeling off his palms, the choking smell of lighter fluid enveloping him.

"He said his body was on fire," said Harsted, adding that the flames had been extinguished. "You could actually see the muscles in his hands. His skin was peeling off."

Antoine Willis Jr., 19, was sleeping in the 1300 block of Ames Avenue in St. Paul when his mother's 54-year-old boyfriend allegedly doused him with lighter fluid and set him ablaze just before 7 a.m., police said. The motive is unclear, but authorities are investigating a link between the fire and a physical altercation involving multiple people, including Willis and the suspect, that occurred several hours earlier, said officer John Keating, a department spokesman.

Willis and his girlfriend, who smothered the flames with a blanket, fled the house with two younger children, Harsted said. They said Willis had intervened earlier in a fight between Willis' mother and her boyfriend. Willis and a friend or friends apparently beat up the boyfriend, who later obliquely warned him not to go to sleep, Harsted said.

Police would not confirm the story, but another neighbor said that about 7 a.m. Wednesday, the suspect asked to use the phone because there had been a family fight. Dried blood caked his nostrils, she said.

Meanwhile, Harsted, his girlfriend Mariah Green and Green's sister, Roquena Carter, tended to Willis, who paced around their home with his arms outstretched, palms facing up.

His lips were raw and red, his hair singed and his face burned.

"I'm on fire. I'm burning. It hurts," Willis said. "I can't believe he tried to kill me."

Harsted was told by 911 dispatchers to instruct Willis to splash cold water on his burns until EMTs arrived. After a few tries, Willis gave up because the pain was too excruciating, Harsted said.

"I wouldn't wish that on anybody," Green said.

As an ambulance arrived for Willis, police were handcuffing the suspect as he sat on the other neighbor's stoop. The suspect was taken to Regions Hospital and then to the county jail. He has not been charged.

Willis was taken to Regions, where he was listed in fair condition. His injuries are not life-threatening, police said.

Neighbors said the suspect was friendly, always stopped to talk and attended their parties on occasion. But police and court records show a different side.

The suspect has convictions for 5th-degree assault and domestic abuse violating a no-contact order in Anoka County, both involving Willis' mother. He was ordered to attend domestic abuse counseling.

Police records also show that there have been 24 police calls to the family's home between September 2009 and this June, seven of those for domestic situations.

Antoine had spent most of his life with his grandmother, Mary Willis, until moving out of her home in Brooklyn Park and moving in with his mother in St. Paul.

"How a man could do this, none of us know what to say," Willis said.

Chao Xiong • 651-735-1762