Greensboro, NC -- Guilford County Sheriff B.J. Barnes issued a news release Tuesday morning confirming that Mary Ann Holder was the only shooter involved in the shootings on November 20, 2011.
Barnes said ballistic testing revealed that the gun found in Mary Ann Holder's hand was the same weapon used in the shootings that killed five children and injured a man. He said that cell phone records also confirm the location of Mary Ann Holder for all the shootings.
SLIDESHOW: View photos of the victims and suspect
Investigators said on the morning of November 20, Holder shot her son Robert 'Dylan' Smith, 17 and his 15-year-old girlfriend Makayla Woods, along with her niece Hannaleigh Suttles, 8 and nephew Richard Suttles, 17 in her home on Cocoa Drive in Pleasant Garden.
Holder then drove to the GTCC Aviation Center near the airport. That is where she shot Randal Lamb in the arm. Barnes said that Lamb and Holder had been an affair at one time.
After shooting Lamb, detectives said that Holder picked up her son Zach, 14 at a friend's house. She shot Zach in her car, before turning the gun on herself.
Dylan Smith was the only one of the victim's pronounced dead the day of the shooting. The other four children died from their injuries over the course of the next week.
Sheriff B.J. Barnes said there is still no clear motive as to why Mary Ann Holder shot all the victims.
Court documents revealed that Mary Ann Holder had given one of the victim's Randal Lamb, a check made out to his wife in the amount of $10,000 the day before the shootings.
Major Tom Sheppard with the Guilford County Sheriff's Department said the check was a "settlement" to Jennifer's threat to file an alienation of affection lawsuit against Holder. It is unclear what role that transaction may have played into her actions.