Dexter Lewis, 22, one of the suspects, stood silently, staring at the judge, as he made his first court appearance just hours after his arrest.
He was advised of the potential charges against him then led from the courtroom in chains, mouthing "I love you" to his mother Tammesa Jones, in the gallery.
She later said her son is an artist who is expecting a baby with his fiance.
"This is not something he would ever do," she said. Moments later, she fell sobbing into her sister's arms.
Court records indicate that Lewis pleaded guilty to robbery charges in Jefferson County in 2008. There was no indication of a sentence being handed down in the records.
The others arrested for investigation of murder, robbery and arson were Joseph Hill, 27, and his brother, Lynell Hill, 24. Charges have not yet been filed.
The fire occurred about 2 a.m. on a poker night at the bar. Firefighters found the bodies of one man and four women, including the owner of the bar, 63-year-old Young Fero.
The medical examiner identified the other victims as Daria M. Pohl, 22; Kellene Fallon, 45; Ross Richter, 29; and Tereasa Beesley, 45. Pohl, Fallon and Beesley were from Denver. Richter was from Overland Park, Kan.
Investigators were led to the three suspects by tips received after a news conference. Saunier believes the men had been to the bar before.
An arrest warrant was issued for Lynell Hill on Oct. 9 for failing to appear in what began as an assault case in suburban Arapahoe County. He later pleaded guilty to harassment by striking, shoving or kicking, according to court documents. A lawyer who represented him in that case didn't immediately return a call seeking comment.
Lawyer Sara Garrido, who represented Lewis in his robbery case, remembered him as "very articulate and very nice" and said he didn't seem like the kind of person who would commit the crimes in the bar fire.
"He was very sweet, very intelligent," said Garrido, who was a public defender at the time but is now in private practice. She didn't remember the outcome of the case.
Lynell Hill was expected to appear in court Friday, but Denver County Court Judge James Breese rejected a request by the media to have a photographer in the courtroom, citing the ongoing investigation.
He also ordered court records sealed.
The bar is in a strip mall about five miles south of downtown Denver, just beyond the upscale Cherry Creek North shopping district. The bar attracted both regulars and people staying in nearby hotels, but neighbors said it didn't seem busy most days.
Frequent patron Chris Brady said customers ranged from "semi-homeless-looking people" to patrons in suits and ties. He was at the bar Tuesday and left about 11 p.m.
"There was nobody random or crazy in there," Brady said.
Brady said Fero was known for cooking up beef dishes at a moment's notice and usually closed the bar herself. She bid Brody goodnight Tuesday as he paid his tab.
"She said, 'Thank you, sweetie. Have a good night,'" Brady said. "I said, 'You too.'"
Jerry Richardson, who maintained an ATM at the bar, described Young Fero as feisty.
"When she wanted that machine fixed, she would tell you about it," Richardson said.
A man who answered the door at an address for Pohl declined to comment. Neighbors Bert and Suzanne Kasben described her as studious.
"She was always working," Bert Kasben said, adding he knew she held several waitressing jobs.
The Kasbens said Pohl was one of three sisters in a tight-knit family who often were seen walking their dog in a quiet cul-de-sac.
Beesley was listed in state records as the owner of Maxim Lounge, another Denver bar.