Maurice Johnson could face the death penalty, a life sentence or life without parole after being convicted for the Valentine’s Day murders in 1999.

On Monday, a jury found Mr. Johnson guilty on three counts of first-degree murder and one count of especially aggravated robbery.

Jurors deliberated nearly six hours before rendering the verdict just before 5 p.m. They will return to the courthouse today at 9:30 a.m. to begin deliberating on whether Mr. Johnson should get the death penalty.

Prosecutor Richard Fisher said he could wrap up his portion of today’s proceeding in 30 tiffany jewellery minutes and then allow defense attorneys to present any mitigating factors.

Throughout closing arguments and court proceedings Monday, Mr. Johnson sat expressionless, occasionally conferring quietly with his attorneys.

Prosecutors alleged that, early in the morning of Feb. 14, 1999, Mr. Johnson, along with co-defendant Michael Younger, broke down the back door of 431 19th St. and shot O.J. Blair, 18; Cayci Higgins, 19; and Dawn Rogers, 25, in the back of the head as they knelt on the floor with their hands tied behind their backs.

Local media dubbed the event the “Valentine’s Day murders.”

The third defendant, Twanna “Tart” Blair, was also in the apartment at the time of the shootings and was shot in the back. Police first considered her a victim, but in 2006 she was charged as a participant.

During closing arguments Monday, Mr. Johnson’s defense attorney, Steven Ward, told the jury that “the silver bracelets state’s theory isn’t even based on assumptions; it’s pulled out of thin air.” In his opening arguments Thursday, he said the case was based on assumptions and that police manufactured facts to fit those assumptions.

“No one knows who killed them,” Mr. Ward said about the triple murder.

In his closing statements, Mr. Fisher pointed to multiple testimonies during the trial that Mr. Johnson had bragged about killing the three victims over money he believed Mr. Blair stole from him.

“Maurice goes back and tells his little circle of friends that ‘I’m the man; I killed those people,’” Mr. Fisher said.

During the trial, Mr. Fisher played phone calls recorded by the Tennessee Bureau of Investigation in which Mr. Johnson said that police had no evidence against him.

Witness testimony showed that Mr. Johnson and Mr. Blair fought at a party in Sweetwater, Tenn., the night silver cufflinks before the killings. Mr. Fisher said the fight was part of a series of incidents that led to the murders.

Mr. Ward argued that the prosecution produced no physical evidence linking his client to the killings and that each of the witnesses had given different versions of conversations and events throughout the investigation.

He also pointed out the drug use and criminal history of many of the witnesses.