It's how police officers gather information about drivers at a traffic stops, or know who has a warrant out for their arrest.
It's called LEIN -- or the law enforcement information network -- and only officers have access to it.
"It's for law enforcement purposes only," Lansing Police Chief Teresa Syzmanski said.
But Lansing Police Officer Lori Williams, an eight-year veteran with the force, is accused of using the database inappropriately. She was arraigned in Ingham County Wednesday on four counts of misuse.
What the inappropriate behavior entailed, Chief Syzmanski can't say.
"This was an investigation by MSP, a criminal investigation that was taken to the Ingham County Prosecutor's office.
MSP would not comment on its investigation, but forwarded News Ten the rules of LEIN, one of which clearly states: "a person shall not access, use, or disclose information from LEIN for personal use or gain."
The police union declined to comment on camera, but its president told News Ten these are still accusations, he'll wait to make judgment until after the investigation is complete.
Until then, Officer Williams is on paid administrative leave.
Szymanski said all Lansing Police officers are tested every two years on the rules of LEIN, and must pass with a 70 percent or higher.
"We do audits quite frequently," Syzmanski said. "The MSP does audits, it goes back to our testing policies."
But something was missed in this case, and Chief Szymanski said they are taking it very seriously.
"This is not common, this does not happen every day or month, this is very rare," she said.
On top of criminal charges, the Lansing Police Department is conducting its own internal investigation.
Whether or not criminal charges result, Officer Williams could face a permanent suspension or termination from the force if the internal investigation proves she violated department policy.