Dixmoor police are reopening the case of a 14-year-old girl murdered in 1991 and will get help this time from the Cook County Sheriff’s Office, officials announced Wednesday.

Five teenagers were charged and convicted in the murder of Cateresa Matthews, but they were released from prison in 2011 after DNA evidence excluded them. The so-called “Dixmoor Five” served 19 years each in prison and were later granted certificates of innocence by the state.

A 2012 lawsuit by the five claimed that Dixmoor Police knew the DNA evidence excluded them but that officers beat confessions out of them anyway. The suit also alleged that police linked the DNA to a sex offender who had been released on parole shortly before the murder.

That person, who was behind bars as of 2012 for other offenses, has never been charged.

Sheriff Tom Dart — who has a history of investigating cold cases, such as that of John Wayne Gacy — said he got involved after Dixmoor Police Chief Ron Burge appealed to him for help.

Dart would not address specifics of the case or the DNA but said his team, with Dixmoor Police, would be re-investigating all aspects of the case.

“We are collectively going to be working to bring justice to Cateresa Matthews and her family,” Dart said.

Burge, a former Dolton police chief who was appointed Dixmoor chief in January, said he grew up next to Matthews’ mother and knew the girl personally.

“I saw her grow up, so this is somewhat personal. I reached out to the Sheriff’s Office because they have the capability and manpower” to of investigate a “case of this magnitude.”