Vehicle wont start

With engine cranking, do you have spark at the spark plugs? You can check spark by pulling plug wire where applicable. Use spark tester or known good spark plug in the boot. Ground metal part of spark tester to metal part of engine, watch for spark, engine cranking. If you have coil on plug ignition, no plug wire, you can still do the same thing, remove the coil and use spark tester. If you have spark everywhere, use a gage and check fuel pressure. Some of the national brand autostores used to loan out a fuel pressure gage.

What about your security system? Do you think that might be causing an issue?