Disney theme parks, SeaWorld Orlando and Universal Studios have all installed metal detectors in time for the holiday season.
"We are enhancing security measures at all of our parks for the busy holiday season, including increased security presence both inside and outside the parks," SeaWorld Parks & Entertainment said in a statement. "Guests entering SeaWorld Orlando can also expect thorough bag checks as well as metal detector checks."
SeaWorld San Diego did not specifically confirm the use of metal detectors, but park officials said: "The safety of our guests and team members along with the welfare of our animals have always been our top priority … Like other major attractions and venues, we continually evaluate our existing comprehensive security plans. We are enhancing security measures at all our parks for the busy holiday season, however, we do not comment on the details of our security measures in order to maintain their effectiveness."
The Orlando Sentinel reported that wand metal detectors are being used to check guests at the SeaWorld park in Florida.
Metals detectors -- now common at airports, courthouses and other public buildings -- are also being used at Disneyland parks in Anaheim and Disney World in Orlando, as well as at Universal Studios Hollywood, as concerns grown across the country about outbreaks of violence in crowded public places.
"We have begun testing metal detection at our theme park," according to a statement from Universal Studios Hollywood. "We want our guests to feel safe when they come here. We've long used metal detection for special events, such as Halloween Horror Nights. This test is a natural progression for us as we study best practices in today's world."
At Disneyland, guests will be randomly selected to go through metal detectors as part of the new safety protocols, which also include the cessation of toy gun sales and a ban on costumes for patrons 14 and older.
"We continually review our comprehensive approach to security and are implementing additional security measures, as appropriate," said Suzi Brown, a spokeswoman for Disneyland.
After guests have their bags checked by security, some will be randomly chosen to go through portable metal detectors, much like the ones used at major sporting events, an official said.
The theme park has beefed up the number of uniformed police officers outside the company's parks in recent weeks. Officers are also increasing the use of "vapor wake dogs" that are specially trained to detect residue from explosives.
Toy guns will no longer be sold in Disney theme parks and hotels, but they can still be bought at Disney's outlying retail stores and online. Toy guns won't be allowed in the parks either.
Guests 13 and younger may still wear a costume to the park.
San Diego Zoo Global issued a statement that said it maintains security personnel and systems at the San Diego Zoo and the San Diego Zoo Safari Park.
"Our operations folks work closely with authorities to monitor changing situations and make adjustments as necessary," according to the zoo. Officials declined to release any details of security measures, saying such disclosure would render them less effective.
Kenneth Bell, who brought his daughter Aliya to the zoo, said, "You can't be too careful. It's not that huge a measure to make sure people in the park are safe. You don't need to be coming in with anything to set off a metal detector so why worry about it?"
Deborah Monson, her husband and four children agree that safety is most important.
"I think it's a fantastic idea because we don't have police patrols inside the parks. Adding security on the way into the park helps ensure family safety as they're walking around the park and it can help you feel more secure, especially with the amount of tourism it helps locals feel secure inside the park," said Monson.
Metal detectors have been in play at Del Mar Fairgrounds for years. Spokesperson Linda Zweig said, "99.9% of the people are very happy to go through. Our folks are highly trained and sometimes there's a bit of a line but it moves very fast. But it is very thorough as well. There's a bag check and metal detector and every guest who comes to the San Diego County Fair, Scream Zone and other events, do go through security."
Sentek Global Security CEO Eric Basu told 10News, "In this day and age, when you can go to a company holiday party and get attacked, the threat is increasing. It's absolutely critical. Metal detectors are a great first step but you have to have a comprehensive security plan. Metal detectors are going to create operations management problems. You have to continue the bag checks, you have to do a certain amount of profiling people. If somebody sets off a metal detector, you have to have experienced people decide, 'Is this a real threat or is it OK?'"
The theme parks did not reference any specific event that precipitated the move. But concerns about violent outbreaks at crowded public venues have been heightened in recent weeks following the terrorist attacks in Paris and San Bernardino.
The Paris attacks targeted a concert hall, soccer stadium and cafe, while the San Bernardino attack occurred during a holiday party at a treatment facility for people with developmental disabilities.