They often shave their heads in fulfillment of a vow.
"One witness, who declined to give her name, said a man walked into the Jewish Federation building with a gun, said he was upset about what was going on in Israel, then opened fire. After the shootings, the man said to call 911, the witness said. The witness said the man identified himself as an American Muslim."
http://seattlepi.nwsource.com/local/279302_shooting28ww.html