Anthony Alexander Padgett, 36, was taken into custody in the area of Broadway and H Street in Chula Vista late Thursday morning in connection with the spate of violence, during which two of the victims were set on fire, according to San Diego police.
Padgett has since been booked into San Diego Central Jail on suspicion of two counts of murder, two counts of attempted murder and one count of arson. Nisleit declined to disclose a suspected motive for the assaults.
In response to a reporter's question, Nisleit said it was unclear if Padgett, a Chula Vista native, was homeless himself.
According to media reports, Padgett was convicted of mayhem and sentenced to four years in prison for a 2010 attack on a 49-year-old homeless friend, who was also set ablaze, in Chula Vista.
Investigators do not believe there are any outstanding suspects in the case, Nisleit said.
On Wednesday, Mayor Kevin Faulconer and police Chief Shelley Zimmerman called the effort to identify and capture the assailant, who began attacking transients last weekend, the primary law enforcement priority for the city.
During an update Thursday morning, Nisleit said the “very violent person'' carrying out the brutal attacks may be using public transportation and urged bus and trolley riders to be on the lookout for him.
Surveillance cameras at a convenience store near where the first victim was found captured images of a man believed to be Padgett.
Padgett is believed by investigators to be the suspect seen in surveillance video buying gasoline shortly before the body of a slain homeless man was set ablaze, Nisleit told reporters.
That was the first of the two killings, he said.
About 8 a.m. Sunday, Padgett allegedly killed 53-year-old Angelo De Nardo of San Diego and set his body on fire in an open area off the 2700 block of Morena Boulevard in Bay Park, according to police. An autopsy determined that De Nardo died prior to being set ablaze.
Shortly before 5 a.m. on Independence Day, transient Manuel Mason, 61, was found bleeding from wounds to his upper body near Valley View Casino Center in the Midway district. He remains hospitalized in critical condition.
Less than 90 minutes after the assault on Mason was reported, 41-year- old drifter Shawn Longley was discovered dead at a park on Bacon Street in Ocean Beach.
About 5 a.m. Wednesday, a 23-year-old homeless man was gravely injured in the area of Broadway and State Street, and a towel he was sleeping under was doused with a flammable liquid and set ablaze, according to police.
The victim, whose name has not been released, was hospitalized in extremely critical condition and had a poor prognosis for survival, officials said.
Authorities have declined to disclose the cause or causes of the targeted men's non-fire-related injuries, though Nisleit said all four victims had suffered significant trauma to their upper bodies.
Over the last five days, police have been warning the homeless to protect themselves by remaining vigilant and aware of their surroundings at all times, avoiding sleeping alone on the streets and staying in open, well-lit areas.
Late this morning, Father Joe's Villages, a major local homeless services provider, announced that it was seeking funding to provide additional beds at its downtown St. Vincent de Paul Village shelter as a means of helping protect those who have nowhere else to stay.
Zimmerman told reporters on Wednesday that she had made bringing in the perpetrator of the attacks her officers' primary objective as they go about the rest of their daily duties.
“These evil acts of violence are some of the worst that I have seen in my 34 years in law enforcement,'' Zimmerman said. “This killer has targeted some of our city's most vulnerable citizens while they are asleep.''
Faulconer said police officers were fanning out to make those in the transient community aware of the attacks and to keep them safe.
“These crimes against some of our city's most vulnerable people are absolutely reprehensible,'' Faulconer said.
This evening, Nisleit said detectives would be reviewing other recent assaults against the local homeless population to determine whether they might be related to this week's series of attacks.
Anyone with information that could be pertinent to the investigation was asked to call San Diego County Crime Stoppers at 888-580-8477 or contact the agency online at sdcrimestoppers.org.