ORLANDO, Fla. (CBSDFW.COM/AP) — A judge overseeing a misdemeanor stalking charge involving former neighborhood watch volunteer George Zimmerman has warned attorneys not to attempt to retry a previous murder case that ended with his acquittal.

In this handout image provided by the Seminole County Sheriff’s Office, George Zimmerman poses for a booking photo on April 11, 2012 in Sanford, Florida. (credit: Seminole County Sheriff’s Office via Getty Images)

The judge on Wednesday told attorneys at Zimmerman’s pretrial hearing not to “open old wounds.”

Zimmerman is accused of sending threatening messages to a private investigator who had contacted him about a documentary series about Trayvon Martin. Martin is the black, unarmed teenager Zimmerman fatally shot in 2012 in the Florida city of Sanford.

Zimmerman was acquitted of criminal charges because of Florida’s stand your ground law.

The documentary is being produced by rapper Jay Z.

A sheriff’s report says private investigator Dennis Warren received numerous calls and texts from Zimmerman in December.

The judge granted a request from Zimmerman’s attorney to allow the investigator to be deposed.

Zimmerman didn’t attend Wednesday’s hearing.

In 2013, Zimmerman was armed when he was stopped for speeding in North Texas. He was given a warning and allowed to leave after being pulled over while traveling westbound on Highway 80 in Forney, a Kaufman County city about 20 miles east of Dallas.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)