Renny Nunez, 47, was charged with murder, and is currently in a local hospital in critical condition from a self-inflicted gunshot wound.
The standoff unfolded at an apartment complex on Katy-Flewellen Road near Gaston.
Nunez was brought out on a stretcher after reportedly shooting himself in the head while he was barricaded inside an apartment.
Suspect found with gunshot wound to head
Authorities say this all started when Nunez called his sister to say that he killed Rebecca Fuenmayor Soto in the parking lot of her Harris County apartment.
Soto was dressed for work when he confronted her and found her speaking to another man in her complex, officials say.
Witnesses at the scene of the deadly shooting told ABC13 they heard a man yelling to call the police.
He and the Soto were reportedly arguing. According to a witness, she was shot after that.
Investigators say Nunez also told his sister that he was going to his own apartment in Fort Bend County to kill himself.
The sister then called the Fort Bend County Sheriff's Office.
Swat scene in Fort Bend County
During the standoff between Nunez and SWAT, deputies were heard shouting commands at him.
Nearby apartment residents were removed from the area as a safety precaution.
After the complex was cleared, the SWAT Team released tear gas canisters into Nunez's apartment.
That's when they found him alive and breathing inside the apartment with a self-inflicted gunshot wound.
He was lying near the front door.
Man in SWAT standoff believed to be suicidal
Authorities say the couple have a two-year-old together. Officials were concerned that a baby was inside the apartment during the standoff, but later determined the child was at another location with a relative.
Deputies also said there appeared to be domestic issues between the couple within the past ten days. They added that both Nunez and Soto had visited their offices separately before to report an issue.
Fort Bend County Sheriff Troy Nehls says his agency will work with the Harris County Sheriff's Office on the investigation.
Swat scene unfolding in Fort Bend County
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