A pro-Palestinian man is in custody after allegedly killing two Israeli embassy staffers outside the Capital Jewish Museum in Washington, D.C. late Wednesday. Police said the victims were a young couple who were about to be engaged.

Slain staffer Yaron Lischinsky had purchased an engagement ring and was planning to propose to his colleague Sarah Milgrim.

The two embassy employees were killed by a gunman Wednesday night after an event at the Capital Jewish Museum.