From
http://www.deathpenaltyinfo.org/federal-laws-providing-death-penalty
Take your pick. There are quite few laws defining federal crimes that suspect 2 could be charged with and subject to the death penalty if found guilty.
18 U.S.C. 844(d), (f), (i) Death resulting from offenses involving transportation of explosives, destruction of government property, or destruction of property related to foreign or interstate commerce.
requires interstate commerce or federal property
18 U.S.C. 1111 First-degree murder.
no federal agents were killed, no attack occurred on federal property or at maritime
18 U.S.C. 1121 Murder of a State or local law enforcement official or other person aiding in a Federal investigation; murder of a State correctional officer.
read the rest of my posts, yes this is possible IF the MIT officer was aiding the Feds
18 U.S.C. 2332a Murder by the use of a weapon of mass destruction.
requires proof of interstate commerce or attacking federal property
21 U.S.C. 848(e) Murder related to a continuing criminal enterprise or related murder of a Federal, State, or local law enforcement officer.
continuing criminal enterprise is aimed at organized crime