Sources: Airport security experts from Israel and the United States. Graphics reporting by Hugo Martin @latimesgraphics Comparing security measures at LAX and Ben Gurion International LOS ANGELES INTERNATIONAL Cars checked randomly The roadside check for cars oper - ates on a random basis. A computer program determines dates, times and duration of the program. Armed police with K-9 on patrol Armed airport police and K-9 units patrol the airport grounds and terminals on foot, bicycles, motorcycles and in cars. Behavior detection officers Specially trained TSA officers question passengers to try to spot potential terrorists, but only at 87 of the nation’s 450 major airports. Security checkpoints Passengers take off their shoes, belts and coats before undergoing a full-body scan. Sticky notes Security agents affix a sticker that includes a set of numbers on each passport. The numbers start with one through six, with one representing a passenger with very little risk and six representing a serious security threat. Luggage X-rayed before check-in All luggage is X-rayed before the check- in process, with suspicious items put in blast-proof containers and taken to a safe area for examination. Metal detectors Passengers go through a screening process without removing their shoes or throwing out bottles of water or baby formula. Security in checkpoint lines Passengers waiting in checkpoint lines may be questioned. Agents can also ask to open their email accounts or Facebook pages for inspection. Armed guards question passengers Outside the terminal and near the entrance, armed guards can question passengers or do random checks. Secu - rity personnel have access to passenger lists so they can cross-check them with lists of suspects under surveillance. All cars stopped by armed guards Outside the airport, cars are stopped, drivers and passengers are questioned and vehicles can be inspected. BEN GURION INTERNATIONAL Luggage X-rayed after check-in All luggage is X-rayed again after check-in. Luggage X-rayed after check-in Carry-on bags are screened by X-ray machines. Checked bags are screened by X-ray and CT scanners. 3564785689 6384750609 Note: Graphic shows only a select few security measures disclosed to the public.