Two adults have been charged after a 7-year-old brought a gun to a Grand Rapids, Michigan, elementary school, authorities said Tuesday.

The charges stem from a May 3 incident in which a second-grade student brought an unloaded gun in a backpack to Cesar E. Chavez Elementary School, Kent County Prosecutor Chris Becker said in a news conference.

The child's mother, Aubrey Wilson, 32, was charged with child abuse in the fourth degree, a misdemeanor.

The mother's fiancée, Chelsea Berkley, 29, faces a charge of being a felon in possession of a firearm, a felony. She is in custody on unrelated charges, according to a release from the City of Grand Rapids.

"Essentially what we have here is one individual brought the gun into the home and the other individual was the one who put the gun in a place accessible to the child that brought it to Cesar Chavez Elementary," Becker said.

It is unclear if Wilson or Berkley have retained attorneys.

The charges mark the latest in a series of cases against adults responsible for elementary school-aged children who brought guns to school. In January, a teacher at an elementary school in Newport News, Virginia, was shot by a 6-year-old student who brought a gun to school in his backpack, police said.

"Getting illegally possessed weapons off our streets is critical to our children's safety," Police Chief Eric Winstrom said Tuesday. "Keeping legally possessed guns secure and out of the hands of kids is critical to our children's safety. We, together as a community, all have a role to play in keeping our children safe."

The police chief said that just a week after the child was found at school with the semi-automatic handgun, another elementary school student turned up to school with a loaded handgun.

"I have about 23 years of police experience and I will say this is the first time and now the second time that I've ever encountered a child that small having a gun in school ... and to see it twice in one week period was very alarming," Winstrom said. "To see an 8-year-old walk into school with a loaded gun shortly thereafter was astounding to me."

The loaded gun was found inside a third grader's backpack at Stocking Elementary School, CNN affiliate WXMI reported.

The gun discoveries on school grounds prompted the school district to announce a ban on bringing backpacks to school.

Grand Rapids Public Schools announced last week it is banning backpacks, citing four confiscations of handguns from students this academic year alone, according to a statement from the district.

Another Michigan school district, Flint Community Schools, also banned backpacks as of May 1, citing safety concerns.

The bans across the two Michigan districts come at a time when schools across the US are grappling with how to prevent and prepare for potential gun violence on campuses as more mass shootings make headlines.

According to a CNN count, there were at least 16 shootings at K-12 schools in the US in which at least one person was wounded from the beginning of the year through March 27, when six people, including three children, were killed in a shooting at the Covenant School in Nashville.

"Across the country, we have seen an increase in threatening behavior and contraband, including weapons, being brought into schools at all levels," Flint school officials said in announcing their ban.