SAN DIEGO — The alleged serial killer of the city's homeless was himself sleeping on the streets.

Police announced Friday they had arrested Jon David Guerrero, 39, for stabbing and torching people while they slept on the streets. Guerrero was collared on three counts of murder, two counts of attempted murder, and two counts of arson. The first attack the nightstalker is accused of happened on July 3 and ended in the pre-dawn hours of July 15 when a homeless man was seriously wounded in the chest. Police apprehended Guerrero, who matches the physical description of the killer, before 8 a.m.

Capt. David Nisleit announced at a press conference that evidence collected from Guerrero’s "residence" and several crime scenes “definitively and uniquely” linked him to the attacks.

Tina Calderon told The Daily Beast that Guerrero was a fixture at Kimball Park just off D Avenue, in the predominantly Hispanic town of National City, which neighbors San Diego. Calderon positively identified Guerrero when she was shown a photo of him from survillence video and before she was told of his arrest.

"He goes past here all the time riding on a whitish-grey bicycle at about 5 o'clock in the morning," she said.

Calderon was warned recently to steer clear of the loner who was known around these largely Hispanic haunts as "kind of scary."

"He sleeps by the church and he was one of the people who ate there," she said, referring to Southport Christian Center.

There was no easy sleep for the homeless like Calderon thanks to Guerrero's alleged crime spree. For the past two weeks, people on the streets have been sleeping with one eye open, cuddling up with any blade they can find thanks to the gruesome attacks that began on July 3.

“Guys who been on the streets a long time are scared to sleep alone,” a 52-year-old man who gave only his first name, Rick, said before the arrest.

Though the homeless have been here before after police said last week they nabbed the serial killer when they arrested Anthony Padgett for the murders. On Monday, they released him.

“We found exculpatory evidence that doesn’t give me confidence with moving forward for Padgett to remain in custody,” Nisleit told The Daily Beast on Wednesday.

Padgett’s criminal case was tempting for police though.

According to the criminal file, Padgett doused a 49-year-old fellow homeless pal named Sidney Moreno with alcohol before lighting him up in what the detective and witnesses described as a “bombfire.” The blaze, which was witnessed by a pair of BMX bikers, consumed over 30 percent of Moreno’s body with second- and third-degree burns.

After Padgett’s release and before Guerrero’s arrest, many were scared to death.

“It feels safer in jail than out here,” a 43-year-old homeless tattoo artist named Sean said. “There’s more honor among thieves in jail than there is honor among homeless out here.”

Sean (who, like many we spoke to, gave only his first name) brandished a six-inch Milwaukee duct knife that he holsters on the right side of his pants.

“I don’t fuck around,” he said, sitting on concrete steps directly across the street from where the very first victim was slain. “I used to just carry a pocket knife and now that this happened I have something on my hip at all times.”

Sean said he was overcome with sorrow (and set flowers down at the site with a female friend) when the killer’s first victim, a drifter believed to be from the Pacific Northwest named Angelo DeNardo, 53, was murdered and then set alight under the overpass where Interstate 5 crosses. The killer apparently used a gasoline accelerant in the heinous act around 8 a.m. on July 3.

Cops believe the homicidal maniac bought the gasoline he used to fry his victim at a Shell gas station a few blocks from where the body was found.

The Daily Beast tracked down a clerk, who said he sold the gas can and one gallon’s worth of gas to a backpack-clutching man who donned gloves, jeans, a green cap, and a tan pocketed jacket. The gas station’s surveillance cameras gave cops their only look at the ghoul.

Elliot was working the 6 a.m. to 2 p.m. shift and said he came face to face with a customer now at the center of a SoCal manhunt.

“Do you guys have gas cans?” he was asked. “Yeah, we do. We sell them everyday,” Elliot responded.

The clerk used a hooked stick to pull a red can from the elevated shelf. At the register the man mumbled quickly. Elliot said he “was talking fast” and “had a unique way mumbling” his words. He also dumped a few bills on the counter before tacking onto the purchase a pack of gum and a Bic lighter.

“He gave me a bunch of cash,” the clerk recalled.

Taking a chance of levity, Elliot told him, “You talk too fast.”

The customer didn’t laugh. Instead, he drew gas from pump 1 and walked down the street toward the train tracks. Not more than 20 minutes later came sirens from fire trucks and police cars.

“There’s a fire down there!” a woman screamed to Elliot at the station, who then handed over the critical footage to police.

The man in the blurry images and a police sketch appear to match Guerrero, right down to the floppy green hat.

“I am confident that the person depicted in that video is our suspect,” Capt. Nisleit said. “That’s the guy who committed three murders and one attempted murder.”

DeNardo was a regular patron at World Gas Station. Owner Miguel Jones said he would come in to buy a premade sandwich, a Dr. Pepper, and a bag of chips, always paying with his food-stamp card.

“He was getting his stuff and then he would go smoke his weed,” Jones told us. “He wanted to go lay down and he was happy like that.”

He asked about what drew the man to town and Jones was told the Golden State was far more giving when it came to disability benefits.

The grisly crime scene is paces away from the heavily trafficked Morena Boulevard. The remote grounds are full of weeds and rocks and shielded away from civilization across the street. Many homeless crash here while a lion-like locomotive roars by at laser speed. It’s now the same charred spot where DeNardo’s life was stolen when he was beaten and torched.

Even though Sean grew up in San Diego, he refuses to return to that camp.

“I’m not going down there anymore,” Sean said. “That’s where we would go and sleep but I’m kind of weirded out.”

The killer struck again a day later.

Manuel Mason, 61, was ambushed at around 4:51 a.m. on Independence Day while sleeping in front of the Modern Times microbrewery in an industrial section of town.

According to Capt. Nisleit, Mason is still fighting for his life.

“It’s day to day,” he said. “Last time we checked we were told he will probably come through. We’re following up everyday and very hopeful he will survive.”

That same day cops descended onto the Peninsula Tennis Club located at Robb Athletic Field located in Ocean Beach. Along a tucked-away trail between the tennis courts and a skatepark at the end of a horseshoe section of the park was 41-year-old Shawn Longley’s mutilated body.

Wednesday a makeshift memorial was set up with flowers and notes remembering the late homeless man who, friends told The Daily Beast, had only arrived in San Diego three days earlier.

A witness who was at the park that day when Longley’s body was found but wished not to be named said that the man had his skull crushed by a rock and that he had his eyes and face “spiked” by a sharp object.

“This guy likes to have fun afterwards and beats you while you’re dying.”

Duane Smith, 49, was collecting cans Wednesday as a softball competition was in fierce display, skaters were volleying at the park, and tennis summer campers were eating their bagged lunches.

“I saw the killer I think,” he said, going on to describe in detail the man wearing the same getup as the customer caught on the Shell gas station surveillance footage buying the gas can. He said he called cops soon after he received a flyer with the man’s mug on it.

“I saw him at around 3 a.m. and he stopped and he was looking at me weird. I wasn’t paying too much attention because I didn’t know he was the killer,” Smith said, adding the man left the park through an alleyway.

“He was wearing gloves and dressed exactly as he was in that picture and had the same look,” referring to close-up still frames taken from the video that appear on the police flyer that has been circulating.

Smith, who collects cans and salvages for loose gold around the park, is one of many homeless who are now packing protection.

“I’m armed when I’m sleeping with different weapons,” he said confidently. “I got a spike and I can take it and go like this in their jaw… If you wake me up the first thing I’m going to do is attack you because there’s no reason you should be messing with a homeless person sleeping in the first place.”

Smith admitted that anybody who is homeless is on guard and “hiding out.”

A 34-year-old homeless man named John recounted how he had been swarmed by cops on the same day they had let Padgett go.

“I was across from the library downtown and somebody seen me walking by called the police,” he told The Daily Beast while sharpening his bicycle tools next to a mammoth palm tree located at Pantoja Park.

John said he let six officers know he was packing a few blades on his person before he was patted down. John denied he was the serial killer and the cops believed him, but not before asking for a DNA sample just in case.

“I said, take it. I’ll spit, give blood, jerk off into a cup—whatever you need I’ll give you.”

John said the cops warned him to remain in San Diego. “I’m homeless,” John said, pointing out the obvious. “I can’t just up and leave town.”

John was plopped down on the park grass not more than 100 yards from the fourth murder.

Dionicio Derek Vahidy, 23, fought for four days before he died on Sunday from “extensive damage to his upper body,” according to police.

The serial killer was no longer content with the outer reaches of San Diego, this time striking the city’s solar plexus in an uppercrust neighborhood called Marina.

One neighbor who was walking his dog that morning expressed discomfort with the homeless population “urinating and jacking off” just outside his pricey digs, but admitted they were human beings and nobody deserved to be disposed of so cheaply. “If you don’t like them that’s okay but you don’t have to hurt them,” the 70-year-old neighbor, who requested anonymity, said.

At a makeshift memorial set at the spot where Vahidy was attacked, a card stood upright, addressed to the victim and read, “You were a beautiful you man. You were so kind.”

Another hand-drawn gravestone in the shape of a cross contained a message from a Kathy and Bailey.

“You are in God’s care now, never go hungry or sleep on the cold ground again.”