Channel 4 has confirmed that a man arrested in Mississippi on child pornography charges last month is now charged with murder, and sexual battery and other counts in connection with the death of Somer Thompson.

Clay County Sheriff Rick Beseler notified the media before dawn Friday that he will announce a major development in the Somer's homicide investigation at noon.

Sources confirmed to Channel 4's Jennifer Waugh that Jarred Harrell -- named a person of interest in Somer's death when he was arrested -- was charged with murder at 6 a.m. Friday.

Team Somer, the group of investigators who have worked on the case since the 7-year-old was abducted and killed in October, will join the sheriff as he makes the announcement. Somer's mother, Diena Thompson, is expected to talk to reporters at 2 p.m.

Harrell, 24, was arrested last month in Meridian, Miss., and returned to Clay County to face 55 charges involving molestation and child pornography.

Clay County deputies said that in October, Harrell lived on Gano Avenue, a house that Somer walked by on her way home from school every day and only a few doors from where the girl was last seen alive. Her body was found two days later in the Charlton County, Ga., landfill where Orange's Park's trash is dumped.

Two weeks ago, Harrell was arraigned on the pornography and molestation charges and pleaded not guilty.

Prosecutors said counts of molestation and using a child in a sexual performance were related to a 3-year-old girl and that none of the charges had any connection to Somer.

Court Documents:

Jarred Harrell Jail Documents (Early March)Jarred Harrell Jail Documents (February)New Arrest Report: Harrell Charged With MolestationHarrell - Clay County Booking SheetHarrell - Mississippi Rendition Warrant

Harrell is being held in an isolation cell and without bond in the Clay County jail. His public defender declined to comment on the case.

When Beseler made a brief statement after Harrell was arrested, he said he would not talk in public again about the Somer murder investigation until there was a major development.

Friday's announcement will take place at the First Baptist Church of Orange Park, the church where Somer's funeral was held.

Channel 4 is carrying this announcement live on both the local station and News4Jax.com.