NATE FULLER'S nightly walks with Bianca, his bichon, will never be the same.

He's used to passing neighbors out with their own pooches. They talk, catch up, learn about one another.

A constant dog-walking companion was James Stuhlman, who lived a block away, on Woodcrest Avenue near 66th Street in Overbrook. Whenever the two met, the conversation would inevitably turn to landscaping, Stuhlman's trade, or "just life in general" as Bianca sniffed Molly, Stuhlman's labradoodle. It was common for Fuller to lose track of time, to stretch those "quick chats" into 90-minute talks.

Now, Fuller is all too aware of time.

"I'm heartbroken," he said last night as sleet fell on his tree-lined street. "I'm still struggling. It still hurts."

Stuhlman, 51, was gunned down March 12 a few yards from Fuller's front door, the victim of a botched robbery by three teenagers.

Yesterday, the kid who allegedly pulled the trigger, Tyfine Hamilton, surrendered to police, Homicide Unit Capt. James Clark said. It wasn't the first arrest on his record.

The 15-year-old and his family arranged a meeting with investigators, on Midvale Avenue near Wissahickon in East Falls, not far from where Hamilton's mother lives, Clark said.

He's been charged as an adult with murder, robbery and related offenses in Stuhlman's slaying.

Hamilton's arrest came a day after police announced that they had captured his two alleged accomplices: Brandon Smith, also 15, and a 14-year-old boy whose name hasn't been released.

Smith also faces a murder rap, police said. Both teens, schoolmates at Overbrook High, have provided full confessions to police, Clark said.

The younger boy, who has cooperated with investigators, will be charged with robbery.

Yesterday, a young woman answered the door at Hamilton's home, on Wanamaker Street near Lebanon - about a mile away from Stuhlman's block. She slammed the door in a reporter's face when he asked for a comment.

Before they allegedly cut down a family man and beloved neighborhood fixture, the trio were shooting hoops at a nearby park, Clark said. They decided they wanted to rob a dog walker, and picked a target at random, Clark said.

Police sources say they acted as if they had done this before - this likely wasn't the boys' first try at robbery, and detectives are currently searching for links to other area attacks.

In any case, that initial mark on Woodcrest Avenue seemed too threatening, his dog too aggressive. So, when they spotted Molly, who seemed "weak," and Stuhlman, who was older than the previous individual, the boys changed plans, Clark said.

The youths walked up to Stuhlman about 8:30 p.m., all wearing hoodies and backpacks. Hamilton allegedly produced a pistol - police still don't know how the boy got his hands on the weapon - and announced the robbery.

Stuhlman pleaded for his life, begging kids young enough to be his grandsons not to shoot him.

A fight broke out. A shot went off.

Stuhlman was hit once in the chest and collapsed, his valuables spilling into the street, where they remained when police arrived. After all that effort, the thieves fled empty-handed.

Officers took Stuhlman to Penn Presbyterian Medical Center, where he was later pronounced dead.

On Wednesday, Stuhlman's life was honored at a funeral at Presentation Blessed Virgin Mary Church in Wynnewood, a "packed service" that included practically everyone who lives on that stretch of Woodcrest Avenue, Fuller said.

He was laid to rest afterward in Ss. Peter and Paul Cemetery in Springfield.

Last night, Helen Farnon, another one of the regular dog walkers on Woodcrest, choked up as she remembered Stuhlman.

"He was so pleasant," she said on her stoop. "He was one guy who knew what was going on in the neighborhood and made sure everyone was doing OK."

He was a thoughtful guy - he tended to the patch of the nearby Morris Park that abuts his property, clearing it of leaves in the fall and snow in the winter.

He was a family man - his daughter, Elaina, often joined him for his nightly walks with Molly.

Farnon was grateful that Elaina stayed home March 12.

She bristled at the mention of the kids accused of killing him, wishing she and her loudmouth pomeranian, Luke, would have been with Stuhlman that night.

"If I had been out there, maybe we could have scared those creeps away."

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