Pennsylvania schools have seen an increase in unsolved bomb threats in its public schools over the past three academic years, but a general decrease in terroristic threats, according to data from the state Department of Education.

An Associated Press analysis of school threat data found the disruptions are increasing nationwide at the expense of students' learning time and local police departments' resources.The state department has provided data gathered annually from Pennsylvania's 500 public school districts. More than 1.7 million students attend Pennsylvania public schools.A look at Pennsylvania school threat statistics from 2012-2014:Unsolved threatsDistricts reported 132 unsolved bomb threats made to and within schools during the 2014-2015 school year. That number is an increase compared to the 88 unsolved bomb threats reported in 2013-2014 and 82 in 2012-2013.Bomb threats are elevated to terroristic threat cases when an offender is identified as having made the threat. Terroristic threat cases include an array of threats made to schools, not only those involving bomb claims.In the 2015-16 year, Panther Valley, Jim Thorpe and Lehighton all experienced a rash of bomb threats.Terroristic threatsPennsylvania schools saw a general decline in terroristic threats during the 2014-2015 school year with 548 cases compared to 560 cases in 2013-2014 and 565 in 2012-2013.Terroristic threats include solved bomb threats and any direct or indirect threat to commit violence to terrorize, evacuate buildings and create public inconveniences.Pennsylvania schools have recorded more than 500 terroristic threat cases each year since the 2009-2010 school year.Firearms and BB gunsHandgun, rifle or shotgun and other firearm possessions are some of the rarest weapon possessions in Pennsylvania schools. They collectively increased with 62 cases in 2013-2014 compared to 42 in 2013-2014 and 48 in 2012-2013.Handguns were more common than rifles or shotguns and firearms each year.Schools reported 156 students in possession of a BB or pellet gun in 2014-2014, but the small increase from the previous year's 139 reported incidents was low in comparison to years that recorded up to 229 BB or pellet gun cases.Other weaponsStudents were most commonly in possession of knives during the 2014-2015 in comparison to other weapons. Pennsylvania schools recorded 1,279 cases of students in possession of a knife that school year.Administrators and law enforcement responding to school threats must quickly evaluate them to determine how to respond.They consider:TYPE AND DETAIL:Is the threat of a bombing, a shooting, or other specified or unspecified violence? It is vague or presented with details, such as an exact target, time or location?Responses can vary significantly depending on this information.A vague threat at a multi-school campus might lead to evacuations or lockdowns affecting many more people than a threat against someone specific in a particular class.DELIVERY:Schools receive threats via phone calls and messages, paper notes, messages written on school property, emails, social media and other forms.Sometimes the method of delivery helps officials determine who's responsible for the threat and whether real harm might be imminent because they can, for example, trace a Facebook post to a particular account or assess whether a call came from out of state.MOTIVE AND CAPABILITY:Learning the responsible party's motive, such as getting a class canceled or hurting someone who has wronged them, and information about whether the person would actually have the means and ability to follow through on a threat also can help determine its legitimacy.PLANNING:How a school has planned for or practiced various responses, such as lockdowns and evacuations, can also factor into whether such orchestrated options are used in threatening or emergency situations.