A January school shooting at Perry High School near Des Moines, Iowa, which left two dead and six injured, was “the product of significant preparation and planning,” by a lone shooter, a new report released by the Dallas County Attorney’s office found.

The shooter's online activity before the attack is under thorough investigation in order to determine a motive.

The student gunman in a small-town Iowa school shooting in January in which two people were killed and several others injured was known to have a fascination with school shooters and exhibited a number of unreported “warning signs,

Iowa Department of Public Safety commissioner says there was evidence of "copycat behavior" in the Jan. 4 Perry school shooting.

The shooter responsible for two deaths and multiple injuries at an Iowa high school earlier this year “likely displayed warning signs” according to a detailed report from state officials released Friday.

The Iowa Department of Public Safety says the 17-year-old student responsible for killing two people and injuring six others acted alone.

The Iowa Department of Public Safety held a news conference Friday morning to release more information about the investigation into the deadly January 4th shooting at Perry High School. Six people were injured and sixth-grade student Ahmir Jolliff and Principal Dan Marburger died when Dylan Butler,

"This investigation ranks among the most exhaustive and complex investigations the DCI has undertaken in its 100 year history," DPS Commissioner Stephan Bayens said.