CHICAGO (CBS/AP) — A 21-year-old man has been charged with the murders of his grandparents, longtime CTA bus driver Gabriel Tyson and his ex-wife Carmella, who took him in when he was released from prison.

Romel Tyson has been charged with two counts of first-degree murder in the stabbing deaths of his grandparents in south suburban Markham.

Police described the scene as “horrific” and “bloody.” Markham Police Chief Terry White said there were signs Gabriel Tyson tried defending himself, given the blood spatter all through the house. Romel Tyson had recently moved into the house, because he had nowhere else to go after getting out of prison.

“Police said it’s the worst thing they’ve ever seen,” said neighbor Fran Jurek. “How in the world could you ever think of that?”

Gabriel Tyson, 68, affectionately known as Gabe, spent 20 years working as a CTA bus driver and lived on Sawyer Avenue in Markham for decades.

Gabriel Tyson

Gabriel Tyson

“We’ve been neighbors for over 27 years,” Jurek said.

And the Jureks new something wasn’t right when one of Tyson’s grandsons frantically knocked on the door.

“The grandson came over here and asked if we had a key,” Jurek said.

“No one in the house was answering their phones,” added Kristyn Jurek.

So that grandson called 911. When Markham police arrived on the scene, they found Gabe Tyson lying in a pool of blood near the back door. Once inside, they found Tyson’s ex-wife – Carmella Tyson, 65 – dead in the room, also stabbed to death.

Police said Romel Tyson, who had been living with them in a bedroom, sitting calmly among kitchen knives. Police said he had recently moved in after getting paroled from prison in June. The grandfather had allowed the 21-year-old to stay with him.

“He had a good heart to let someone stay with you,” Fran Jurek said. “I sure, I wouldn’t if someone just came out of prison. I’m sorry. And I’m a Christian woman.”

Neighbors are grateful they didn’t give spare keys to the worried grandson.

“Thank God I didn’t find it, because he would have came in there and saw the scene,” Kristyn Jurek said.

What sparked the double murder remained unknown Tuesday night. The grandson will appear before a judge on murder charges later this week.

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)