The FBI is investigating an individual by the name of Gabriel that has been talking to an undercover agent about providing information to a group of people who are residing in Europe that will assist them in conducting attacks in the United States support of their ecological beliefs. Gabriel is a United States citizen who works for the US Department of environment where he obtains information for the group. Several potential crimes may have been committed. These might include, treason, sedition, espionage and terrorism.

Define the elements of each of the above crimes and explain if any of the crimes may be charged against either Gabriel.