CHICAGO (CBS) — The family of a man who was killed in his cell at Cook County Jail is suing the sheriff and the county, saying 19-year-old Pedro Ruiz never should have been locked up with a cellmate who had a documented history of attacks on fellow inmates.

“What happened to Pedro Ruiz in the Cook County Jail, while in Cook County’s custody, was not just easily preventable, was not just forseeable, but was absolutely disgraceful,” said Ruiz family attorney Nenye Uche. “It was easily preventable, definitely foreseeable.”

Pedro Ruiz (Source: Cook County Sheriff)

Last week, 24-year-old Christian Gonzalez was charged with first-degree murder in Ruiz’s death. Prosecutors said he beat Ruiz to death using a sock filled with bars of soap half an hour after Ruiz was placed in his cell on Feb. 1.

On Tuesday, Ruiz’s family filed a wrongful death lawsuit against Gonzalez, Cook County, and Sheriff Tom Dart.

Uche questioned how Gonzalez could have beaten Ruiz to death and guards at the jail didn’t hear anything while it was happening.

“The Cook County Sheriff’s office and the correctional facility is liable – absolutely liable – for an execution based on incompetence, and that’s what this case is about,” he said. “How is it possible that an inmate is beaten viciously and violently for 10 to 15 minutes at 2 a.m., where you can only hear a pin drop, where the jail is on lockdown, and not a single guard hears a scream. How is that possible?”

Christian Gonzalez (Source: Cook County Sheriff)

Gonzalez had been in the jail since June 2, 2019, when he was arrested on charges he used an assault-style rifle to shoot a man in 2017.

Ruiz was arrested on Jan. 29, after police identified him as a suspect in a recent shooting which left a man with multiple gunshot wounds. He was placed in a Cook County Jail cell with Gonzalez on Feb. 1, shortly after being booked into the jail.

Not only were Gonzalez and Ruiz members of rival gangs, but sources said Gonzalez – who already was being held without bail on the attempted murder charges from last year – had been caught on video in November 2019 as he and four other inmates put another detainee in the hospital after a vicious beating.

After the November beating was over, video shows Gonzalez throwing a joker card from a deck of playing cards onto the victim’s lifeless body. Sources said this points to ongoing feuds inside the jail.

“How is it possible that an inmate who had a propensity, and a documented history of vicious attacks against other inmates is left in a cell with another inmate, and not isolated or segregated? How is that possible?” Uche said.

The sheriff’s office has declined to say why Ruiz and Gonzalez were placed in a cell together, and has said it has launched an internal investigation into all of the factors in the case.

Sources with knowledge of Ruiz’s death said a jail officer was doing a security check on the area where the two were being held on Feb. 1, and when the officer got near their cell, Gonzalez told the officer “Something is wrong with my cellmate.”

The officer saw Ruiz standing with his back against a wall. He didn’t appear to have visible injuries.

The officer notified his sergeant of what Gonzalez said, and then two sergeants and a lieutenant checked the cell, unlocking the door to find Ruiz lying on the floor, covered in blood. Sources said Gonzalez – who is known to have multiple disciplinary incidents – was handcuffed.

Officers started chest compressions on Ruiz, and called 911. An officer used an automated external defibrillator on Ruiz while others continued chest compressions. When paramedics arrived, they took over chest compressions, and put Ruiz on a gurney to take him to Mount Sinai Hospital, where he was pronounced dead.

Ruiz’s sister, Yulissa, said the attack could have been stopped.

“It could have been prevented if this guy, Gonzalez, would have been separated from other inmates,” she said.

Yulissa said she feels lost without her brother.

“I feel more than devastated,” she said. “I miss him, and nothing is going to take away this pain. We want justice, answers, and the most evidence to show us how this happened to him.”

Uche said he plans to file for subpoenas demanding video from cameras for every floor of the jail at the time of the attack, for records from the jail’s gang intelligence unit, and for information on every person responsible for the placement and classification of inmates.

“They have to give the family answers, and that’s really what they want. That’s what this is about, because it’s unbelievable to me that in the world’s number one democracy, the United States of America, an inmate is getting beat to death in a jail for 10 to 15 minutes, and absolutely no one hears,” he said.