AUSTIN, Texas - "He asks about him every once in a while and I can't say anything."
I just don't know what to say to him," Hellen Spears told Fox 7 Tuesday morning referring to her 2-year-old son Noah.
Spears said 25-year-old Amir Azad was Noah’s dad.
"Even though we split apart he was always trying to get us back together and I really wanted him to work on himself, it's just not fair. He really didn't live. He didn't live out his life," Spears said.
Round Rock Police Chief Allen Banks said early Sunday morning around 5:30 someone called 911 about a man walking near I-35. When officers arrived, they found Azad's body near Old Settlers Blvd.
"The driver of that car did not stop at the scene so at this point we're actually looking for any witnesses," Banks said.
On Twitter Tuesday afternoon, Round Rock Police asked if anyone has a dashboard camera who also happened to be driving on I-35 between 5 and 7 Sunday morning. The department said "even if you think your footage is insignificant, we'd like to see it."
"I just really want to know like who hit him and just left him there, left him there dead and couldn't stop...what kind of person could be so heartless?" Spears said.
"Your first instinct should be 'Oh my God, let me stop' you hit somebody and you keep going and...I mean just thinking about it is heartbreaking," said Hellen's sister Rebecca Spears.
Rebecca said they need answers for Hellen and Noah's sake.
"Who knows how fast they were going? He might have been dead on impact the first time, who knows he could have survived it if it wasn't as bad. But we'll never know that. We will never know that," Rebecca said.
Hellen said she's been in touch with investigators at Round Rock Police who said they would keep her updated.
She said Amir was still trying to get his life together. He had just texted her the night before asking her back.
"I was like 'I'm not ready for a relationship right now and I don't think you are either.' But he never saw that," Spears said. "I just know there's a lot more to the story like he can't just be walking on the highway. It just doesn't sound like something he would do right before asking me for another chance, it just doesn't make sense."
Hellen said she doesn't hate the driver who did this but she does want that person brought to justice.
"It would be so helpful if the person just came forward, I know it's hard. I know they're probably freaking out right now but like it would leave me with so much peace in my heart," she said.
Round Rock Police said officers Charles Whites who was hit while directing traffic shortly after remains in "serious" condition Tuesday.
The department is asking for prayers. The driver who hit him did stop and is charged with intoxication assault.
Round Rock Police say if you have any information about who hit Amir Azad, give them a call.