(CNN) -- Brandi Fernandez, interim district attorney for Kaufman County, is a very capable and competent prosecutor, one of the Texas county's top elected officials says.
Fernandez, who was the top assistant before Mike McLelland and his wife were slain in their home, has worked for the department for the past nine years.
County Judge Bruce Wood called her a very capable attorney.
Fernandez has earned a reputation as a tough opponent for defense lawyers.
"She definitely knows what she's doing," Wade Gent, a criminal defense attorney from Kaufman told CNN Dallas affiliate WFAA. "For the most part, she's by the book, no-nonsense and will do the job. I have no doubt she is capable of handling the pressure; Brandi is very experienced, very dedicated."
Another defense attorney told the Dallas Morning News that Fernandez was a "beast."
"She strikes fear in some people's hearts," Eric Smenner told the paper, adding that she was tougher to negotiate plea deals with than other prosecutors, but that compromise wasn't impossible.
Fernandez, 42, was the lead prosecutor in a case against a member of the Aryan Brotherhood of Texas, the Kaufman Herald reported in August. James Patrick Crawford was found guilty on six charges in connection with what the paper called a gang-related shooting in 2011.
She has worked at the DA's office since 2004, according to a bio released by the agency.
She was picked by the late McLelland to be the first assistant district attorney when he took office in 2010, a post she also held from 2004 to 2006.
Before that, Fernandez was an assistant district attorney for the 106th Judicial District Attorney's Office in north Texas.
Fernandez graduated from Texas Tech University School of Law in 1996. She was a member of the board of barristers and national mock trial team.
She will serve as interim DA until Gov. Rick Perry picks a successor.