Fifteen-year-old Lamonte Clayborne of Seattle often complained about doing maintenance work around the apartment building his mother managed.
A neighbor in the building once heard him talking about having his mother killed, authorities said.
On Wednesday night, the boy turned himself in to Garden Grove police as one of two juveniles suspected in the fatal stabbing of his mother, Ange May Reed, 41. Her body was found in her apartment last Friday, Seattle detectives said Thursday.
Clayborne fled the low-income Seattle neighborhood in his mother's car soon after the killing, along with two friends identified as Dolphy Blue Jordan, 16, and a 15-year-old, both of Seattle, said Dan Donohoe, a spokesman for the King County, Washington, prosecutors office.
That night, after Reed was found with multiple stab wounds to her face and throat, Seattle police got a call from the 15-year-old, who had fled from Clayborne and Jordan during a rest stop near the Oregon-California border, Donohoe said.
Seattle police then issued a bulletin alerting Orange County authorities that the pair apparently were headed for their territory, Garden Grove Police Lt. Chuck Gibbs said.
About 8:15 p.m. Wednesday, Clayborne called Garden Grove police from a telephone booth at Bolsa Grande High School.
"He just said he was wanted for murder," Police Lt. John Wood said. Clayborne was arrested and taken to Orange County Juvenile Hall in Orange.
On Thursday, Jordan, who allegedly carried out the killing, surrendered to authorities in San Bernardino County, where he is in Juvenile Hall, Donohoe said.
Clayborne and Jordan, who claim to be gang members, have agreed to forgo extradition and return to Seattle with detectives sometime next week to face first-degree-murder charges, Donohoe said.
The third youth told investigators when he returned to Seattle that he had overheard Clayborne talking about killing his mother but didn't take it seriously, Donohoe said.
No charges were filed against him because he had no direct role in the slaying, Seattle police spokesman Don Church said.
One week before Reed's death, Clayborne told a neighbor that he wanted to find a gun to kill his mother, Donohoe said. A day before the slaying, he told the same neighbor that he wanted to hit the woman over the head with a baseball bat, throw her body out the window and toss it into a swamp in Everett, Wash., 30 miles north of Seattle, he said.
According to police reports, Jordan attacked Reed in the hallway of her apartment about 2 p.m., after she got out of the shower. She was first hit over the head with a stick, police said, and then stabbed repeatedly with a kitchen knife.
The 15-year-old told police that he and Clayborne waited in the victim's car, Donohoe said. The murder weapon later was found on a Seattle freeway overpass, he said.
Jordan apparently has relatives in San Bernardino County, but it was unclear to investigators or Orange County authorities what brought Clayborne here, Donohoe said.
"It was believed they had some connections with California," he said.
Mike Hogan, the King County deputy prosecutor who filed the charges, said the pair apparently gave away Reed's car after they arrived in Southern California. Authorities recovered it at the U.S.-Mexican border.
Clayborne and Jordan each are being held on $500,000 bail. If convicted, they could be sentenced to jail until age 21. Then, if tried as adults, they could face from 20 years to life in prison, he said.
The youths have had some run-ins with the law, Hogan said, but have no history of violent behavior.
"It's just a weird case," he said.