Evolv said sales to at least one major customer included terms and conditions that exceeded the company’s standard contracts and that “certain company personnel engaged in misconduct in connection with those transactions.”

It’s another headache for Evolv, which already faces a shareholder lawsuit as well as investigations by the Federal Trade Commission and the Securities and Exchange Commission. Critics of the company say it has made false and exaggerated claims about the effectiveness of its system, which uses metal detectors and artificial intelligence software to detect people carrying guns.

Evolv shares were also hit in May after the company cut its revenue guidance for the full year 2024. And the New York Daily News reported earlier this month that the city’s Department of Investigation is looking into possible improprieties in the decision to to test Evolv systems in some subway stations in New York.

In addition, Evolv recently announced new clients including Spectrum Center, home of the NBA’s Charlotte Hornets, and Moda Center, home of the NBA’s Portland Trail Blazers. Evolv systems are used at Gillette Stadium, Fenway Park and TD Garden.

Hiawatha Bray can be reached at [email protected]. Follow L @GlobeTechLab.