DENVER - The final man accused of killing five people at a Denver bar during a robbery learned Thursday that prosecutors are going to pursue the death penalty.

Denver prosecutors had until Friday to decide whether to seek capital punishment for 23-year-old Dexter Lewis. On Thursday during the afternoon hearing, they announced their intentions.

"This case is a case that cries out for the death penalty," Denver District Attorney Mitch Morrissey said. "We have a man and four women who were allegedly laid down on the floor of a bar and were butchered. Based on that, I think it's appropriate for us to seek the death penalty."

Former Denver prosecutor Craig Silverman noted the political environment of the decision.

"[Morrissey] made a strong point that he's a different kind of Colorado Democrat," said Silverman, noting the recent decision by Colorado Governor John Hickenlooper to indefinitely postpone the execution of Nathan Dunlap.

Lewis and two brothers, Joseph and Lynell Hill, were implicated in the slayings by a federal informant who said he went with them to the bar in October.

The Hill brothers reached plea deals earlier this week and the informant hasn't been charged.

According to investigators, the informant said Lewis stabbed the bar's owner and four others multiple times while the brothers held them at gunpoint.

They also allegedly set the bar on fire and left with $170.

A man who identified himself only as Tracy told 9NEWS he believes Dexter Lewis, his nephew, is innocent.

"I believe he's not guilty. He's my nephew. He told me he's not guilty. He's a good kid," he told members of the media after the hearing.