A jury convicted and sentenced Leonard Dawson to 75 years in prison for murdering his girlfriend, Harris County District Attorney Kim Ogg announced Wednesday.

"Domestic violence drives the murder rate in Harris County, and this case is an example of what we see time and time again," said Ogg. "We know the victim was scared to come home, and with good reason. This is an issue we all have to take head on in order to keep people safe."

When Houston Police officers initially interviewed Dawson, 30, he told them he was home with his girlfriend, Julia Green, and their infant son on July 12, 2014.

He said she handed him their child and she went to the bedroom. Dawson said that moments later he heard a single gunshot. He told officers that when he found Green, he picked her up, moved her, and placed a towel on her neck to stop the bleeding.

Dawson later told other Houston Police officers a slightly different story, citing an argument he had with his girlfriend. His story also ended with the girlfriend shooting herself in the neck, but in this version Dawson said he caught her before she hit the floor.

Police determined that the evidence at the scene did not match the stories Dawson was telling them and not consistent with a suicide. An autopsy determined the cause of death to be homicide.

"Dawson kept changing his story, but we were able to show the jury beyond a reasonable doubt that he was guilty of murder," said Assistant District Attorney Gilbert Sawtelle. "We thank the jury for their service to the community.'

In addition to the murder conviction, the jury was presented with several additional offenses committed by Leonard Dawson, including two sexual assaults, an aggravated robbery, and an assault of a security officer.

Dawson is sentenced to 75 years in the Texas Department of Criminal Justice.

The case was prosecuted by Sawtelle and Assistant District Attorney Erica Robinson.