ST. PETER — A state investigation has found the Minnesota Security Hospital improperly restrained a patient with a history of aggressive behavior early this year.

The report released Wednesday said the patient at the St. Peter mental hospital was placed in restraints or seclusion 55 times in one month, and in one case was confined for more than 17 hours.

The state Department of Human Services oversees the hospital. It pledged a year ago to eliminate the use of restraints and seclusion at state-licensed facilities except in emergencies.

Deputy Human Services Commissioner Anne Barry said the St. Peter hospital has initiated new mandatory employee training and has reduced the use of restraints. Patients spent 31 hours in restraint and seclusion in September. That’s down from 174 hours in February, when the violation occurred.