Harris County Constable Lt. Charles Hoover told NBC News that the girl, who was struck in her shoulder near her neck, suffered non-life threatening injuries. It was unclear if she was still hospitalized, he added.
The man, who Hoover declined to identify, was in his 40s and was not related to the victim, Hoover said, adding that he was charged with deadly conduct.
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UNITED STATES - SEPTEMBER 10: Yvonne Crasso, holds a picture of her sister Nina Michele Bradley, who was killed by a gun at age 23 in 2012, during a rally on the East Front lawn of the Capitol to demand that Congress take action on gun control legislation, September 10, 2015. Ashley Cech, whose mother Yvonne Cech, a librarian, survived the Sandy Hook shootings, appears with Crasso. The event, titled #Whateverittakes Day of Action, was hosted by Everytown for Gun Safety and featured speeches by political leaders and families of gun violence victims. (Photo By Tom Williams/CQ Roll Call)
WASHINGTON, USA - JANUARY 4: A group of people demonstrate in front of the White House for greater gun control to help curb gun violence in Washington, USA on January 4, 2015. (Photo by Samuel Corum/Anadolu Agency/Getty Images)
WASHINGTON, DC - DECEMBER 10: Natasha Christopher, center, holds up a photo of her son Akeal Christopher, who was 14 years old when he was shot in the back of the head and killed while walking home in Brooklyn, New York, during a press conference, on Capitol Hill on December 10, 2015 in Washington, D.C. The conference featured supporters of gun control and family members of gun violence victims. (Photo by Allison Shelley/Getty Images)
WASHINGTON, DC - DECEMBER 10: Miyoshia Bailey cries as she describes how her only son, Cortez Bailey, 23, was shot to death in Chicago, Illinois, during a press conference, on Capitol Hill on December 10, 2015 in Washington, D.C. The conference featured supporters of gun control and family members of gun violence victims. (Photo by Allison Shelley/Getty Images)
WASHINGTON, DC - FEBRUARY 05: Rep. Elizabeth Esty (D-CT) (L) and Sen. Richard Blumenthal (D-CT) are joined by Newtown Action Alliance Vice Chairman David Stowe (R) to announce the re-introduction of legislation that would ban high-capacity ammunition magazines at the U.S. Capitol February 5, 2015 in Washington, DC. Citing the 2012 mass shooting of children and teachers at Sandy Hook Elementary in Newtown, CT, Democratic members of the House and Senate joined the Connecticut delegation to support and emphasize the need for the proposed law. (Photo by Chip Somodevilla/Getty Images)
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The incident happened on Saturday around 5 p.m. CT in Spring, a small suburb north of Houston, during what Hoover said was probably a barbecue.
"We come around here to get home and there's two people playing, like they're having a water gun fight," neighbor Rasheed Seals told NBC affiliate KPRC.
Then one of them — the man in his 40s — went to his car to get dry clothes, another neighbor, Micah Stewart, told KPRC.
"He must have had the gun so he started playing with it. I thought he probably had it on safety and he accidentally shot the girl in her collar bone area," Stewart said.
"It was crazy, like you would never expect somebody to bring a gun to a barbecue, or a family gathering at all," Stewart added.
Citing an ongoing investigation, Hoover declined to provide additional details surrounding the shooting.
A bullet also hit a car five houses away, KPRC reported.
"Don't play with guns, not the right choice," said Seals.