By Jamie Gumbrecht, CNN
(CNN) - It's not the first time this has happened: Students return to school after a few weeks off, and a few things have changed. Maybe the gym floor got a shine, the new physics teacher arrived - or there's an adult with a gun.
As students across the country returned to school this week, some schools implemented new security policies or brought in new personnel. Some are temporary or pilot programs. Others are refreshes of existing plans and training.
In Utah and Texas, some educators trained in shooting or self-defense. Arizona's Maricopa County Sheriff Joe Arpaio put a "posse" of armed volunteers around school perimeters. The National Rifle Association said all schools should immediately have armed officers, later adding that schools should decide for themselves how to protect children.
It's all in reaction to the December 14 shooting at Sandy Hook Elementary School in Newtown, Connecticut, where 20 children and six staffers were killed.
“This is Columbine déjà vu,” said Kenneth Trump, a school security consultant who works with school districts across the country. For weeks he's been hearing from schools that want to review emergency plans, train staff or invest in technology they hope will increase security.
"I’m happy to see these conversations happening now," Trump said. "I’m frustrated you couldn’t pay someone to have those conversations the day before Sandy Hook."
A lot has changed for Sandy Hook students. They returned to school last week in a different building in a different town. The school was outfitted with familiar rugs and furniture - even the school's pet turtle made the move.
In his State of the State address on Wednesday, Connecticut Gov. Dannel Malloy emotionally rejected the idea of guns in schools, whether teachers carrying weapons or guards outside every classroom.
But Sandy Hook students did return to a school with more cameras, more locks and an obvious police presence nearby.
"I think, right now, it has to be the safest school in America," Monroe Police Lt. Keith White said on the students' first day back.
"Right now" is the timeline security pros struggle with. Trump expects schools to keep calling until budget decisions and new crises draw their attention.
"There’s a buzz at the local level," Trump said. "The question is always going to be sustainability, a dollar cost and time cost. Are you willing to do those things?"
Next week, Schools of Thought will consider five perspectives on how to make schools safer, but for now, here are some security shifts we've heard of across the country.
Starting this fall, all incoming freshman at San Diego State University will undergo "active shooter" training, where students learn how to respond, fight back or set up barricades between themselves and a shooter. Other universities have used the training, too.
In Marlboro Township, New Jersey, the mayor shifted police officers to each school for at least 90 days, until they've done a full security assessment. The officers will be paid from the Board of Education's budget.
In San Antonio, the owner of a self-defense and fitness studio began to offer free self-defense classes to anybody who works for a school, CNN affiliate KENS reported.
It's not yet in place, but Arizona's attorney general proposed a plan to arm principals or another designated person. Budgets are too tight for armed school resources officers on most campuses, Attorney General Tom Horne said.
The Utah Shooting Sports Council is stepping up courses that offer free firearms training to teachers.
What changes have you noticed in your school's security policies, training or staffing? Do you like the changes or not? Share your perspective in the comments.