Three months after a family of six was found butchered in a Gage Park home, Chicago police announced a relative of the family and his teenage girlfriend were charged with killing them after what police said was a robbery turned deadly.

Police and the Cook County State's Attorney's office confirmed Thursday afternoon 22-year-old Diego Uribe Cruz, a relative of the family, and his 19-year-old girlfriend Jafeth Ramos were arrested. Each is charged with six counts of first-degree murder.

The family of six was found stabbed, beaten and shot on Feb. 4, their bodies scattered inside a bungalow on a quiet street in the 5700 block of South California.

"They were a family like any other who went to work, went to school, loved each other and abided by the law," Chicago Police Supt. Eddie Johnson said.

The victims were later identified as a couple, their son, their daughter and their daughter's two children: 62-year-old Noe Martinez Sr., 58-year-old Rosaura Martinez, 38-year-old Noe Martinez Jr., 32-year-old Maria Herminia Martinez, 13-year-old Leonardo Cruz and 10-year-old Alexis Cruz.

Authorities say Uribe, a relative of Maria Herminia Martinez, attempted to rob the family inside the home and shot Martinez during a verbal argument.

"The offender first engaged in an argument with Maria. She was shot and killed and then as time went on, systematically, when he encountered the other subjects in the house, he proceeded to beat or stab them," Chicago Police Chief of Detectives Gene Roy said.

Authorities claim Ramos was present and an accomplice to the killings, but would not specify how.

Since day one of the monthslong investigation, mourning relatives and community members have asked who would do this and why.

Investigators found no signs of forced entry at the home and said all the doors were locked when they arrived. Former Interim Police Supt. John Escalante, however, said one theory — that of a murder-suicide — had been deemed implausible.

Three types of knives or other bladed cutting instruments were used to carry out most of the killings, according to investigators, but those weapons were not at the crime scene. A rifle was found in the home but did not match the weapon used in the shooting death.

Last month, police had indicated the family may have been slain by multiple killers.

But the break in the case came Wednesday, authorities said, when DNA evidence from Uribe was determined to have been inside the house and cell phone records put his location near the murders. Authorities said Uribe's blood was found outside the house and other biological evidence was located inside the home.

Police also said both suspects admitted to their roles in the murders.

Victims' advocate Dawn Valenti recalled seeing Uribe at vigils and funerals for the family, saying she even comforted the man who would later be charged with their murders.

"He was distraught," Valenti said. "And I thought it was grief."

Neighbors said they remembered that Uribe was the young man, good with kids, who was supposed to pick up the Martinez family's dog-- but never showed.

"In my 28 years, I haven’t seen a case that has hit so close to home for myself and so many others in this department than what was discovered on that cold Thursday afternoon in February," Johnson said.

It was not immediately clear if Uribe or Ramos had an attorney.