Short, overweight and suffering from a heart condition, Ronald J. Dominique hardly seemed a threat, much less a serial killer.

A near-broke nobody who lived with his sister before moving into a homeless shelter, he went willingly, leaning heavily on a cane, when officers came to get him last week.

Even with a meek persona, investigators said, Dominique bound and strangled or smothered 23 men and teenage boys in south Louisiana in what the FBI considered its most urgent serial killing case.

Dominique apparently was able to charm his victims into accompanying him, said Les Bonano, director of investigations for the state attorney general's office.

"He'd meet them on the street, walking or riding their bikes, and just start talking to them. He'd offer them a ride or talk them into sex and they'd go with him," Bonano said Tuesday.

Dominique, 42, was arrested Friday at a homeless shelter in Houma and charged with two murders. On Monday, authorities filed nine more counts against him and said more charges were possible.

Dominique was being held without bond at the Terrebonne Parish jail pending a Jan. 17 arraignment. A message seeking comment was left with the parish public defender's office, which was assigned Tuesday to represent him.

Joseph Waitz, the Terrebonne district attorney, said he will seek the death penalty.

Once investigators began interrogating him, Dominique eagerly claimed credit for the killings, Terrebonne Sheriff Jerry Larpenter said.

"We'd been talking to him just a short period of time and he just started giving it up," Larpenter said. "I don't know what prompted it. Maybe he just wanted to clear his conscience."

Dominique is believed to have raped his victims before killing them, Larpenter said.

"He's nothing on the street, a nobody. But here he had power. Once he got those ropes on them, they were his," he said.

Until the week of his arrest, Dominique was living with his sister in Bayou Blue, a rural area near Houma, a Cajun community of 32,000 surrounded by bayous and sugar cane fields, where many work in commercial fishing or the oil industry. His camper was parked behind a trailer covered by a broad, wood roof.

Dominique hit the shelter almost penniless. Phillip "Pappy" Breaux, who lives at the shelter, said Dominique told him he had enough money to pay for a room for five or six nights at $10 a night.

"If he hadn't been arrested he could have been here 20 years and nobody would have paid any attention to him," Breaux said. "He complained about his health some, but that was about it."

Investigators said Dominique was charged at least seven times and jailed twice over the years, mostly for minor offenses such as traffic violations, simple battery and disturbing the peace by offensive language.

But one case apparently planted the seed for his later crimes, according to Larpenter.

On Aug. 25, 1996, Dominique was arrested on a charge of forcible rape. He was booked into jail, but the case did not go to trial because the victim could not be found.

Larpenter said Dominique told investigators that brief brush with incarceration left him determined not to go back to jail.

"He said he killed them because he didn't want to get caught," Larpenter said. "But I would think he discovered somewhere on the way to killing 23 that it was not just because of that. I think he discovered he liked it."

FBI Special Agent in Charge Jim Bernazzani said FBI profilers felt this was the most significant current serial killer case in the country in terms of the number of victims and its time span — the killings took place from 1997 to 2005.

"A serial killer like this hides in plain sight," Bernazzani said. "They do not disturb people. That's why they are so effective.'"

All the victims were homeless males, ranging from 16 to 46, all were strangled or asphyxiated and all the bodies were bound. Their bodies were dumped in remote spots in seven parishes.

The break in the case came when an ex-con told his parole agent about getting away from a man who wanted to tie him up for sex, Larpenter said.

Dominique voluntarily gave investigators a DNA sample, which connected him two Jefferson Parish murders, Sheriff Harry Lee said.

"He went along with it, let us take a swab," Lee said. "He was no trouble at all."