Law enforcement agencies throughout Baltimore say they've seen a spike in threats made at schools — even elementary schools — since the mass shooting in Florida 10 days ago.
Baltimore County police have received an increase in calls for possible weapons at schools, school threats and weapons on students, said Officer Jennifer Peach, a department spokeswoman.
Asked which schools, Peach said: "All of them … when I say every school, I mean even elementary schools."
Every call, Peach said, is being investigated as a credible threat until determined otherwise.
County police were investigating a threat made on Snapchat Thursday night of a possible shooting at Lansdowne High School, but as of Friday it was unsubstantiated, the department said.
On the day immediately following the Parkland shooting, a student was arrested at Loch Raven High School in Baltimore County after allegedly bringing a pellet gun to school in a backpack, prompting a lockdown and large police response.
In Harford County, the sheriff's office said that two students were charged after writing a threat on a school desk, and circulating images of the threat digitally to other students on Wednesday. One student reported the threat to officials, and police identified two students who wrote the threat.
The students were both charged as adults with making a threat of mass violence and disturbing school operations, the department said Friday.
"We take these threats seriously and do not consider them humorous in any way. Even if threats are not deemed credible, you can be charged with a crime," said Sheriff Jeffrey R. Gahler in a statement. "School shootings, like the recent one in Parkland, Florida, are tragic events, and should not be used in an attempt to leverage a prank in order to disrupt school operations."
In Anne Arundel County, officials at Lindale Middle School in Linthicum said additional officers were at the school Friday investigating a social media post that included a threat to the school.
"Classes are continuing on a normal schedule, and there is believed to be no threat to students/staff," according to the school's Twitter account.
And in Carroll County, Francis Scott Key High School, North Carroll Middle School and Manchester Valley High School received threats in the past week.
At about 10 a.m. Friday, the area outside Lansdowne High was silent. A marked police car sat near the front door, and officers stood inside the hallway. A supervisor, patrolling in an unmarked car, said nobody was being let in the building and ordered reporters off school property.
"We investigated through the night and were not able to determine that it was a credible threat," Peach said of the threat made to Lansdowne. "But we also were not able to find the originator of the Snapchat photo. So we wanted to increase police presence in the building."
Diana Spencer, a spokeswoman with Baltimore County Public Schools, said Lansdowne principal Kenneth P. Miller notified parents of the threat by phone, text and email Thursday night, and told them that county police would have an increased presence in the area Friday.
Spencer said attendance numbers were not yet available.
"Most kids did show up for school, and classes resumed as normal," Peach said. "We want to reassure people that if we thought there was any potential for violence, we would have the school closed."
If police can identify who made the Snapchat threat, they would consider charging them.
"If there is an appropriate charge we can apply to a threat of a school shooting," Peach said, "we will charge the person making the threat."
Pete Kriscumas, an aide to Baltimore County Councilman Tom Quirk, who represents Lansdowne, said Quirk spoke Thursday night to county police Chief Terrence B. Sheridan and the captain of the Wilkens Precinct.
"Please give time to the men and women of the Baltimore County Police to investigate this issue," Kriscumas wrote on the Arbutus Improvement Association Facebook page.
Quirk did not respond to a phone message Friday.
The Lansdowne PTSA addressed the threat in a post to Facebook, and described a "disturbing post that's going around on Snapchat regarding a threat of a shooting at LHS on Friday. We are taking it very seriously and are on it with authorities."
Baltimore Sun Media Group reporters Libby Solomon and Emily Chappell contributed to this article.