Two young Israeli embassy staffers were gunned down outside of the Capital Jewish Museum in Washington, D.C., on Wednesday night by a suspected pro-Palestinian terrorist.

Police have identified 30-year-old Elias Rodriguez from Chicago, Ill. as the lone suspect in the case. Rodriguez chanted “Free, free Palestine” as he was being detained.

Yaron Lischinsky and Sarah Lynn Milgrim were in a romantic relationship. Wednesday evening, they attended an American Jewish Committee Young Diplomats reception. The event put on so that participants could discuss the humanitarian crisis in Israel and Gaza.

Metropolitan Police Department Chief Pamela Smith said that event attendees saw Rodriguez pacing outside of the museum before he took a handgun and opened fire on a group of four people. The suspect discarded the gun and went inside, where he was detained by security.

Onlookers captured a video of Rodriguez yelling “free Palestine” as he was taken into custody.

The two victims were a couple on the verge of engagement, Israel’s ambassador to the U.S. said.

“The couple that was gunned down tonight in the name of Free Palestine was a young couple about to be engaged,” Leiter said. “The young man purchased a ring this week with the intention of proposing to his girlfriend next week in Jerusalem. They were a beautiful couple who came to enjoy an evening in Washington’s cultural center.”