A mother of three who "lived for her kids" was one of the women killed in two separate attacks just minutes apart.
Jodie Betteridge has been named locally as one of the victims of the incident that took place at around 8.45pm in Redcar on Wednesday.
Paying tribute to her, Theresa Largan, 51, told the Press Association that Jodie was like one of her own children.
"I only saw her last week, I see her all the time, I just can't believe it," she said. "She was always happy, I don't think I ever saw her sad. She took everything in her stride.
"Jodie lived for her kids, I don't think I ever saw her on her own, she always had the tribe with her. I just want the family to know that we are all thinking of her and them."
A floral tribute for Jodie was left near the scene at Byland Close, where a large police cordon remains, and a white forensics tent is still in place outside the modern terraced house.
The flowers dedicated to her said that "thoughts are with your beautiful children".
One 29-year-old man, who asked to be identified only as Danny, said he had known Jodie since they were teenagers, and described his friend as a "lovely girl".
"She was always smiley, she loved her kids - she lived for them. It is absolutely devastating what has happened, I can't get my head around it," he said.
"All of our friends are absolutely devastated, we are beside ourselves. We can't believe this has happened.
"She was special. Everyone she met, she put a smile on their face. No-one ever had a bad word to say about her.
"My heart goes out to those kids. Those poor children, I am a dad myself and I couldn't imagine what they are going through."
Stepmother Louise Betteridge was too upset to talk about Jodie when approached.
Police said both women died after suffering serious injuries, and that a 34-year-old man is currently being questioned over the two deaths following his arrest shortly after the incidents.
Cleveland Police confirmed that they received a report that a woman had been seriously injured at an address in Mapleton Crescent, Redcar, at 8.45pm on Wednesday evening.
Just seven minutes later, at 8.52pm, a second report was received from a member of the public reporting that a woman was being violently assaulted in Byland Close.
Neighbours in Mapleton Crescent said the victim lived alone in the semi-detached bungalow, where there was a small police cordon and two uniformed officers guarding the scene.
The older victim was 46 and the second woman to be killed was 30, Temporary Detective Superintendent Tariq Ali said.
At a briefing at Cleveland Police headquarters, he said the force was not in a position to name either victim.
He would not elaborate on any potential links between the women and the suspect in custody.
He said: "We are treating both incidents as murder enquiries and specially trained family liaison officers have been assigned to the victims' families who are understandably shocked and saddened by these tragic events.
"The enquiry is still in the early stages and it would not be appropriate at this stage to confirm the names or details of the victims or their families.
"The families of both women have requested some privacy whilst they come to terms with these shocking events. Our thoughts are with both families at this time."