An affidavit in support of a search warrant request for a smartphone believed to belong to LAX shooting suspect Paul Ciancia appears to solve one mystery of the attack:

See also: Paul Ciancia Charged With Murder of Federal Officer at LAX.

Who gave the 23-year-old a ride to the airport Friday morning before he allegedly opened fire and killed a TSA agent?

The affidavit says one of Ciancia's roommates told an agent the suspect approached him Friday morning and requested a ride to LAX:

The roommate agreed and transported Ciancia in his black Hyundai Accent to the Virgin Airlines airport terminal. The roommate stated that he only learned of the shooting incident upon returning to his apartment.

The FBI says its request for a warrant to search the contents of the phone was successful.

The bureau says a battery from the phone was found in the bag that Ciancia carried during the alleged attack and that the phone itself, an LG VX9100, was found in that Hyundai.

Credit: Ciancia via the FBI

Credit: Ciancia via the FBI

Agents want to conduct a forensic search on the device to determine if the attack was planned and to delve into the suspect's mental state.

Ciancia was charged with the murder of a federal officer, Gerardo Hernandez, 39, as well as with carrying out an attack at an international airport.

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