The shooting happened in the 4300 block of Stuebner Hill Drive just before 10 a.m., deputies said.
When deputies arrived, Campos said they found the teenager in the restroom with a gunshot wound.
The victim was rushed to a hospital where he was confirmed dead. It was unclear where the teen was shot.
In the hours since responding to the neighborhood, deputies announced the victim's identity and two arrests from the incident.
The victim Dominique McCoy was visiting the home where 17-year-old Reginald Smalls resides, Sheriff Ed Gonzalez said.
"Smalls claimed that McCoy had startled him inside the home, causing him to shoot him. Manslaughter charges were filed against Smalls," Gonzalez tweeted.
A second person, Lekedrick Bowden, 18, was also charged with a tampering with evidence count. Gonzalez said Bowden was also staying at the home.
When Eyewitness News asked if the shooting was accidental, Campos said they're still looking at everything related to the investigation.
"The case right now is very limited," he said. "We're still trying to put all the pieces together."
Investigators said they do not believe there is a shooter on the loose.
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17-year-old shot and killed in NW Harris County, sheriff says