On Wednesday, Daniel Rivera Jr., 33, pleaded guilty to second-degree felony manslaughter and third-degree felony desecration of a human body for Flores' death.
Rivera is set be sentenced on Nov. 6, but because Flores' family — who are from the Los Angeles area — may not be able to return to Utah on the sentencing date, they were allowed to address the court and Rivera during Wednesday's hearing.
Flores' mother, brother, sister and the mother of his 2-year-old daughter all gave statements in court Wednesday, telling how Flores was a good man, and that they felt betrayed by Rivera, who lied to them about their family member's whereabouts.
"He not only killed my son, he killed all of us," mother Leena Flores said through a Spanish interpreter. "My son was a good son."
Rivera, who was charged just two weeks ago for the 2011 death, faces up to 20 years in prison when he is sentenced.
A family friend told The Salt Lake Tribune in 2011 that Flores left California for Utah on May 7, 2011, with Rivera, who reportedly had promised Flores a construction job.
Deputy Weber County Attorney Branden Miles said Wednesday in court that on May 9, 2011, Flores and Rivera got into a confrontation while inside of Rivera's vehicle.
"[Rivera] gained control of a knife, and stabbed [the victim] in the chest," Miles said, while members of Flores' family wept in the gallery. "It penetrated his heart, and he died almost immediately."
Defense attorney Camille Neider told Judge Ernie Jones that the guilty plea was an Alford plea, indicating that while Rivera does not admit guilt, he believes prosecutors could likely prove the charges to a jury.
"He has maintained the death was caused in self-defense," Neider told the court.
Flores' body was found in February 2012, when police received a tip directing them to a home at 3812 W. 4550 South, in Roy.
On Feb. 9, 2012, after three days of digging, police found Flores' body under three to four feet of earth in the backyard of the home.
After Flores' body was found, the homeowner, Sarah Munn, was charged with obstruction of justice for allegedly lying to police.
According to court documents filed in Munn's case, Rivera received a laceration to his face that required medical treatment and 35 stitches on May 9, 2011. Munn initially told police that Rivera — who lived at the Roy home part-time and is the father of three of Munn's children — had received the injury during a road rage incident, then later told police that she caused the cut herself.