Kan. suicide bomb plot latest in series of FBI undercover stings aimed at thwarting terrorism

In this undated photo provided by the Sedgwick County, Kan., Clerk’s Office, a booking mugshot of Terry Lee Loewen is seen. The 58-year-old avionics technician who worked at the airport for aviation firm Hawker Beechcraft, was arrested before dawn Friday, Dec 13, 2013, as he tried to enter the tarmac on Wichita’s Mid-Continent Regional airport in Wichita, Kan., in a vehicle he believed was loaded with high explosives. (AP Photo/Sedgwick County Clerk’s Office)The Associated Press

The arrest of a Kansas man accused of trying to bring a bomb into a Wichita airport marked the latest in a string of undercover operations that have become a successful, widely used domestic counterterrorism tactic.

Court documents detail six months of alleged conversation between Terry Lee Loewen and undercover FBI agents leading up to Loewen's Friday arrest.

The discussions began as vague sentiments about committing "violent jihad" against the U.S., then turned into a plot in which the agents recruited Loewen to use his access to a the airport for a martyrdom operation.

The FBI insists such stings are a vital, legal tool for averting potentially deadly attacks — and juries have returned tough sentences.

But defense attorneys and others say the tactics involve entrapment and violate civil liberties.