A man who allegedly threw a boy off a pedestrian freeway overpass yesterday was occasionally asked to care for the toddler and recently had been sent for psychiatric evaluation, police said.

Matthew M. Higa, a 23-year-old Roosevelt High School graduate, was arrested yesterday in connection with the death of the boy.

Higa allegedly dropped the toddler 30 feet from the Miller Street overpass onto H-1 Freeway at about 11:40 a.m. where one or two west-bound cars struck the boy. The toddler was pronounced dead at the scene at 12:07 p.m. The medical examiner did not release the name of the child.

Police interviewed the boy's mother and her boyfriend last night. Police were trying to determine how Higa got the boy.

The mother said she had left the boy with her father, who was sleeping in their apartment. Her boyfriend was also in the apartment, she said. She said she went to Ala Moana.

Police said the toddler had wandered off and was returned to the apartment earlier in the day.

Higa and the boy's family lived in the same apartment building, said a neighbor who asked not to be identified. The neighbor said the mother's boyfriend often took the toddler upstairs to Higa's apartment.

The neighbor said Higa often displayed odd behavior. He walked up and down the stairs all night and would scream at 3 a.m., the neighbor said. He would sit on the ground in the garage during the daytime, the neighbor said.

Police said Higa had been a patient at The Queen's Medical Center's psychiatric ward as recently as Dec. 11.

Police said Higa occasionally watched the child, but apparently was not related to him. Police did not say where the child lived.

SMOKED A CIGARETTE

Kraig Hengst was working in an apartment garage across the street from the pedestrian overpass where the boy was thrown and saw a man "toss the baby" into traffic about 11:40 a.m. Hengst said he had seen the same man moments earlier walking in the area near the overpass, but it's unclear which direction he came from.

"I saw the baby high in the air. I thought it was a doll at first," said Hengst, visibly shaken. Hengst, 19, said Higa was holding the child on the overpass in one arm. Then, he "tossed it into the air." At least one vehicle hit the toddler, who landed in the far right lane.

Police closed all west-bound lanes of H-1 from the Kapi'olani Boulevard off-ramp to the Pali Highway off-ramp for nearly five hours to investigate, setting off traffic jams on thoroughfares and side streets alike.

The freeway was reopened about 4:30 p.m.

After the boy was thrown, witnesses said they saw the man walking calmly away toward Prospect Street, smoking a cigarette. When he was out of sight, Hengst and a few friends went to the pedestrian overpass to see what had been thrown.

When they realized it was a child, they followed the man on foot and on a bike and called police, giving officers a description of the man and leading them to the suspect, who was found hiding in some bushes near 513 Prospect St. He was taken into custody at 12:15 p.m. for investigation of second-degree murder.

SUSPECT BELLIGERENT

Higa was taken to the main police station but was sent to Queen's psychiatric ward before he could be booked after becoming belligerent.

He was still at Queen's late yesterday afternoon. Higa has four outstanding misdemeanor traffic warrants totalling $2,800. Records show he has 12 prior arrests, but no convictions.

Higa was involved in an Aug. 15, 2004 negligent homicide investigation in connection with the suspected racing death of Andrew Hansen, 20.

Hansen was driving one of three cars apparently racing on H-1 that Sunday morning when he was killed in a wreck near the Alexander Street on-ramp.

Higa was driving a 2001 Acura. He was questioned at a Henry Street location as part of a third-degree negligent homicide investigation, but charges were declined, according to police.

The third car involved fled the scene.

Witnesses yesterday said Higa was quiet when he was arrested. But after a few minutes, while sitting on the road with handcuffs on, he started yelling loudly. "Thank you for everything you have done for my family," Higa said, repeatedly.

'GUY WAS MESSED UP'

Sam Durham, 20, said he saw a man throw the child from the overpass, then walk away, in no hurry to flee the scene.

"He was just walking," Durham said. "He wasn't running."

Durham also said the man had a "thousand-yard stare."

"The guy was messed up," Durham said.

Police did not release details on where Higa was before the death.

But his hospital garments — a teal short-sleeve top and matching shorts — led to questions about whether he had been at a medical facility.

The Queen's Medical Center, the nearest facility with a mental health wing, would not say whether Higa had been a patient previously or had been at the hospital yesterday.

Queen's spokeswoman Rebecca Pollard said in a statement yesterday that the hospital did not have any missing patients. She also said that, "We have not and do not discharge any patients in a clinically unstable condition."

But while Higa apparently was not missing from the hospital yesterday, police said he had been a patient there before and had been admitted as recently as Dec. 11, 2007, after an incident at a Honolulu car dealership in which he locked himself in a car and refused to get out until officers were called to the scene.

Higa was not arrested for an offense but was sent to Queen's for psychiatric evaluation.

Yesterday, Higa indicated to police that he was recently released from Queen's.

Queen's spokeswoman Nicole Pickens said she could not comment on Higa's history as a mental patient at the facility even if police confirmed he had been taken there and provided specific dates. Pickens also declined to say whether Higa was wearing clothes similar to those worn by mental patients in the hospital.

Capt. Frank Fujii, spokesman for the Honolulu Police Department, also declined to comment on whether Higa had been hospitalized recently or where he came from.

Higa graduated from Roosevelt High in 2003.

A classmate said she remembered him as "quiet and weird."

Staff writers Robbie Dingeman and Rod Ohira contributed to this report.

Reach Mary Vorsino at mvorsino@honoluluadvertiser.com.