The District sued three Maryland families Wednesday, alleging the parents fraudulently claimed to live in the city so their children could attend D.C.’s public schools.

The families skirted paying tuition required of students residing outside the District, according to the lawsuit, and the city’s attorney general said he is seeking more than $450,000 in unpaid fees and penalties. One of the parents is a teacher at a D.C. high school, and a woman accused of aiding a family works at a city high school.

“Individuals who commit residency fraud unlawfully take school seats that should be occupied by children who live in the District,” D.C. Attorney General Karl A. Racine said in a statement. “Our office will continue to bring residency fraud cases to deter non-residents from sending their children to District schools without going through the established process that includes paying non-resident tuition.”

The District alleges in three lawsuits that the families collectively sent four children to city schools between 2011 and 2015 without paying tuition.

Schools attended by the children include Ludlow-Taylor Elementary, Dunbar High School, Hardy Middle School and Wilson High School. Annual tuition at the schools ranges from $10,000 to $14,000.

Under D.C. law, authorities seeking redress from scofflaw suburban parents can seek triple the amount of tuition those parents avoided by using a fraudulent D.C. address.

Residency fraud has been an ongoing problem but came under increased scrutiny this past year after a city investigation alleged that more than 30 percent of students at Duke Ellington School of the Arts — more than 160 teenagers — lived outside the city and were not paying tuition. But in October, administrators and parents at the school said the city had determined at least 90 of the accused students live in the District.

The Ellington investigation laid bare the complicated lives of students in an urban school system and the complexities that come with investigating residency fraud.

The D.C. Office of the Attorney General says it has dedicated additional resources to combating residency fraud over the past two years, including more investigators and attorneys.

This is the third batch of residency-fraud lawsuits the city has filed in D.C. Superior Court in the past 10 months, collectively seeking more than $1.9 million in unpaid tuition and damages.

Named in the lawsuits Wednesday are Kiana E. Bennett and Willie E. Bennett Jr., former residents of Hyattsville, Md., who now live in the District; Erika Parker of Bowie, Md.; and Twarnisha Peterson Stokes of Upper Marlboro, Md.

Tarkitta Sedgwick of Forestville, Md., also is named and is accused of helping Parker deceive school officials by signing forms claiming that she was the child’s primary caregiver and that she and the child lived together in Northwest. But Sedgwick lived in Maryland, and the child did not reside with her, the city alleges.

Sedgwick is an employee of D.C.’s Dunbar High School. Bennett teaches at McKinley Technology High School.

The families did not immediately respond to requests for comment.

The attorney general’s office said Sedgwick and the parents repeatedly in documents used D.C. addresses that were not their own to avoid paying tuition. They signed sworn statements claiming to live in the District. Some of the forms included the line: “I understand that providing false information for the purposes of defrauding the government is punishable by law.”

Morgan Smith contributed to this report.