Wesley Mathews stared ahead and didn't look at jurors as the judge sentenced him to life in prison.

The jury deliberated Wednesday afternoon for about three hours before coming to a unanimous decision to give Mathews a sentence of life in the death of his adopted daughter, Sherin Mathews. 

Prosecutors argued the 39-year-old Richardson father killed Sherin in October 2017. 

He claimed she accidentally choked to death on milk. 

Mathews pleaded guilty Monday to a lesser charge of injury to a child in Sherin's death. He was originally charged with capital murder. 

While prosecutors asked the jury to hand down a life sentence, defense attorney Rafael De La Garza argued that Mathews was a good father who panicked when his daughter choked and didn't call for help. 

After the verdict was read, De La Garza called the sentence "cruel and unusual punishment."

Mathews initially told police that Sherin went missing Oct. 7, 2017, after he put her outside because she wouldn't drink her milk. Her badly decomposed body was found 15 days later in a culvert near the family's Richardson home. 

The father's story evolved during the course of the investigation. He originally told police Sherin was alive when he put her outside. He later admitted she died in his presence. 

On the witness stand during the sentencing trial, Mathews said he panicked after his daughter's accidental death. He said he wrapped her body in a blue trash bag and put her in a culvert so she would be near the home. 

RELATED: Richardson father wanted to 'do something nice' when he wrapped Sherin Mathews' body in trashbag

Jury deciding fate of Sherin Mathews' father
Sherin Mathews
Courtesy photo

'Still a liar'

But prosecutor Sherre Thomas argued Wednesday that Mathews' testimony was just another lie. 

She said testimony and medical records show that it's "medically impossible for a child who is 3 years old to stand up and choke to death" as Mathews claimed. 

"It means he's still a liar. It means he killed that little girl. And when he killed her, he panicked," Thomas argued. 

She said Mathews also took the time to clean up after himself and turned off the location tracker on his phone to try to hide what he had done. 

He then did not tell investigators where his daughter's body was. When her body was found, it was so badly decomposed that the medical examiner couldn't determine an exact cause of death. 

"There's nothing left of her, her teeth had fallen out," Thomas said. "He covered his crime. He got away with that." 

De La Garza argued that prosecutors couldn't prove that Mathews killed his child and said he's only guilty of not calling 911. 

During closing arguments, De La Garza walked over to Mathews and placed his hands on his shoulders. 

“This is something he will live with for the rest of his life,” the attorney told jurors.

Mother in court

Sini Mathews sat in the courtroom during closing arguments Wednesday. 

After the judge read the sentence, she quickly left the courtroom without giving a comment to reporters. 

She and Wesley Mathews were both arrested after Sherin's body was found. The couple later lost custody of their biological daughter. 

wesley sini mathews
Wesley and Sini Mathews

A criminal case against Sini Mathews was dropped this year after the Dallas County District Attorney said there wasn't enough evidence against the adoptive mother. 

The couple adopted Sherin in the summer of 2016. Prior to her adoption, Sherin was abandoned by her biological parents in Gaya, India, and taken to a local orphanage in Nalanda. 

Thomas argued that Sherin suffered abuse the entire time she lived in the United States. 

Medical records show the child had five broken bones that were at various stages of healing. 

"One occurred and then another broken bone and then another broken bone and then another broken bone and then another broken bone. Five broken bones in the short time she was here with no valid explanation given for them," Thomas said. 

"That's the tragic little life that she'd had," the prosecutor argued. 

But De La Garza said prosecutors were trying to paint Mathews as an abuser without proof. 

"Don't let them bully you into something that you don't want to do," the attorney argued. 

Dumped body 

Mathews testified this week that he wasn't ready to believe his daughter was dead. He said he believed if her body were near, she might come back to him, much like Lazarus resurrected in the Bible. 

He said he regrets his actions the night his daughter died and realizes he could have done more to help her. 

"It's just not fair that my heart still beats like my child's heart is not," he testified.

Prosecutor Jason Fine said Mathews should've been Sherin's protector. He should've treated her body with more respect. 

"Good dads don't dump their daughters in sewage drains," Fine said. 

He then asked jurors to sentence Mathews to life and act as Sherin's "true protector."

"I ask you to show the love and the care that he claims he has," he said.