Nearly half a dozen school threats have been made across Long Island since the mass shooting in Texas.

Turtle Hook Middle School in Uniondale is just one of the schools that had a heightened police presence this week after a student made an online threat.

School officials and mental health professionals are asking the public to be on the lookout for the warning signs of violence.

Nonprofit Sandy Hook Promise says some of the warning signs include withdrawing from family and friends, bullying, excessive irritability, social isolation, expressing persistent thoughts of harming, making direct threats, bragging about access to weapons and recruiting accomplices for an attack.

Mental health specialists say it's important for parents to find ways to stay more connected to their children.

"Ask more probing questions along the lines of, 'What was the best thing that happened to you today? Who did you sit with at lunch?'", says Dr. Jeffrey Reynolds, president and CEO of the Family and Children's Association.

If parents are concerned about their child's behavior, they need to let the school district know.

"If it's at an elementary school, tell the teacher or call the office and speak with the principal," says Dr. William Johnson, Hempstead Public Schools NYS monitor. "There are guidance counselors at secondary schools and also social workers and psychologists would be happy to help."

Experts also says social media is an issue that parents need to limit and monitor.

They stress, if anyone witnesses a threat to call 911 immediately.