I shut door on car and was walking away and heard sound you hear when door is still open. I went back and sound would not stop. I tried to start car but starter would not engage and tailights were blinking very fast. . I let it sit awhile and went back and it seems like I have a dead battery. Could this be the fault and how would I check this to be sure? Thanks in advance

Sounds like the battery died.
If that's the original battery your ahead of the game.
I've seen these types of weird things happen when a battery is on it's last gasp.

vicrod

Doc here,

Do a Voltage test on the battery, If dead (11 volts or under) try a charge for 6 to 8 hours at 10 amps, Then Get a load test..

Check Your cables for corroded or lose connections, repair as needed.

If that is all good and the problem still exists, you may have an open fuse link and a big short that took it out and lit off the alarm system before it opened..

Check the battery & Cables First..then let us know..

Doc

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