For royals’ visit to Boston, security will be ‘team event’ between UK, US law enforcement

As the Prince and Princess of Wales are expected to arrive in Boston Wednesday for a three-day stay, a sweeping security apparatus will draw on the expertise of law enforcement agencies from the United Kingdom and the United States to maintain safety, experts said.

British law enforcement officials, including members of the Metropolitan Police Service, alongside the Massachusetts State Police, Boston police, and the US State Department of Diplomatic Security Service are part of the overall security operation for Prince William and Princess Catherine, officials said.

Robert McDonald, a retired Secret Service agent, and Simon Morgan, a former royal protection officer, said in separate interviews they expected security teams from both countries to work together smoothly during the visit.

Prince William, heir to the British throne, and his wife, Princess Catherine, are visiting Boston for the second annual Earthshot Prize Award Ceremony.

For members of the royal family, security is provided by members of the Metropolitan Police who will travel to the United States, Morgan said.

“It is a team event — between the UK and US security details working together, and using each other’s knowledge and experience,” Morgan said in a phone interview.

Experts said officers protecting Prince William and Princess Catherine have likely made extensive security plans for the couple’s itinerary following months of preparations by both UK and US authorities.

The couple is expected to make a public appearance at a welcome ceremony Wednesday afternoon at Boston City Hall plaza with Mayor Michelle Wu.

On Thursday, they plan to visit the Chelsea nonprofit Roca, which supports high-risk young people, and Greentown Labs in Somerville, an incubator for clean energy companies.

And then on Friday, the royals are slated to visit Harvard University and the John F. Kennedy Presidential Library and Museum, and will attend the awards ceremony for William’s Earthshot Prize environmental award at the MGM Music Hall in Fenway.

Juliette Kayyem, a former assistant secretary at the Department of Homeland Security, said it is unlikely there is any specific threat against William and Catherine that “would warrant a level of protection” that the couple wasn’t already used to.

“We are a friendly nation and friendly city,” said Kayyem, now the faculty chair of the Homeland Security Project at Harvard’s Kennedy School, in an e-mail.

“For law enforcement, the issue may be less about violence and more about some protest or rally, protected by the First Amendment, that could be disruptive to a crowd or planning,” Kayyem said in an e-mail.

Representatives for the State Department and the Metropolitan police declined comment on security preparations Wednesday.

David Procopio, the State Police spokesman, said in an e-mail: “As with any dignitary protection mission, a rigorous security plan is in place.”

Work on the royal couple’s visit likely began months ago, with British advance teams coming to the city, according to McDonald, who served for more than 20 years with the Secret Service. They have likely been in place for at least the past several days.

UK and US officials would have met at length to work out issues like planning motorcade routes, making security arrangements for public appearances, and conducting sweeps for explosives, according to McDonald.

American officials will cooperate in similar security preparations when US leaders visit other countries, said McDonald who was member of security details for presidents Bill Clinton and George W. Bush, as well as for then-Vice President Joe Biden, before retiring in 2015.

“When the protectees of this country travel overseas, we work in concert . . . with the law enforcement entities in the host country,” said McDonald, now a lecturer of criminal justice at the University of New Haven, in an interview.

“Likewise, from a reciprocity standpoint, we do the very same here,” he said.

Morgan, whose responsibilities included protecting Queen Elizabeth II and other royal family members between 2007 and 2013, said there will very likely be a plan in place for William and Catherine to meet and interact with the public.

In those moments, crowds who come out to meet members of the royal family are usually very welcoming, he said. But security officials will have to balance that access with the need to protect the royal couple in Boston, he said.

“That’s what you’re building towards — to making sure that nothing goes wrong, and their royal highnesses get back on the plane, all safe and well, and come back to the UK,” Morgan said.