A Michigan child care worker has been charged with abuse involving a 10-month-old baby who was in her care. 

The investigation against Samantha Franz started after a witness saw her "being excessively rough" with the child, according to a press release issued Wednesday by the Macomb County Prosecutor's office. 

After that report, authorities reviewed video footage from incidents on March 31 and April 1 in St. Clair Shores. 

"The video footage displays aggressive, forceful, rough, and abusive behavior by Franz upon the crying infant, which resulted in bruises to the infant's arms," the prosecutor's office said. "The St. Clair Shores police were immediately contacted." 

Franz has now been charged with child abuse in the second degree, a 10-year felony, and child abuse in the fourth degree, a one-year misdemeanor. 

She had an arraignment hearing in St. Clair Shores 40th District Court, the prosecutor's office said. A probable cause conference is set for May 9 with a preliminary exam on May 20. 

"The safety and well-being of our children is our absolute top priority. These charges reflect our commitment to holding offenders accountable, and ensuring justice for our most vulnerable members, their families, and the community as a whole," Macomb County Prosecutor Peter J. Lucido said in his statement.