DUBAI—At least two of the 26 suspects sought by Dubai police for the alleged killing of a top Hamas leader appear to have entered the U.S. shortly after his death, according to people familiar with the situation.

Records shared between international investigators show that one of the suspects entered the U.S. on Feb. 14, carrying a British passport, according to a person familiar with the situation. The other suspect, carrying an Irish passport, entered the U.S. on Jan. 21, according to this person. Senior Hamas leader Mahmoud...