Harris, a 34-year-old resident of an Atlanta suburb, was charged with two counts of sexual exploitation of children and six counts of dissemination of harmful materials to minors, according to the bill of indictment from the Cobb County grand jury.
The indictments involve three girls under the age of 18. Harris is accused of possessing digital photos of the genitalia of two of the girls, sending digital photos of male genitalia to two girls and sending "detailed verbal descriptions and narrative accounts of sexual excitement and sexual conduct" four times.
Harris' lawyer criticized the indictments in a Friday press release.
"Despite possessing Ross Harris' cell phone for almost two years, the Cobb County District Attorney has only now chosen to indict Ross for some alleged consensual electronic communications," H. Maddox Kilgore said. " We are concerned that the timing of this indictment is a calculated maneuver to inflame public opinion against Ross on the eve o f jury selection. It is clear that these allegations are wholly unrelated to the accidental death of Cooper Harris."
Cobb District Attorney Vic Reynolds responded with this statement:
"This case will not be tried by the State in the media. The recent indictment is based on advances in electronic forensic analysis in conjunction with recent interviews of newly discovered victims. Had the State delayed charging any further, prosecution of some of the charges would have barred by the statute of limitations."
Police say Harris left his toddler, Cooper, strapped into a car seat under a baking sun for seven hours while he went to work June 18, 2014.
Records show that the mercury topped 92 that day, and police say the temperature was 88 degrees when the boy was pronounced dead in a parking lot not far from his father's workplace.
During a July 2014 hearing, Cobb County police Detective Phil Stoddard alleged that while Cooper was dying in his father's SUV, Ross Harris messaged six women or girls, sending and receiving explicit texts -- some including nude images -- during work.
Three of the recipients of Ross Harris' messages were underage, the detective said in a January 2015 hearing.
Last fall, a judge said he would not separate the murder and sexting charges at trial.
Harris has been held without bond in the Cobb County Adult Detention Center since June 2014 on the murder charge and the district attorney's office recommends no bond on the new charges.
An arraignment date on the sexting charges has not been set. Jury selection for the murder trial is scheduled for April 11.
Last month Harris's wife, Leanna Harris, filed for divorce.
CNN's Eliott C. McLaughlin, Devon Sayers and Chandler Friedman contributed to this report.
