Former Rep. Ron Paul (R-Texas) took to Twitter Monday to respond to this weekend's fatal shooting of former Navy SEAL Chris Kyle.

The suspect who allegedly shot Kyle and another man is Eddie Ray Routh, a veteran who authorities believe may have a mental illness related to his military service.

Paul wondered what Routh was doing at the Texas shooting range:

Kyle was the most lethal sniper in U.S. military history, with 160 confirmed kills. After leaving the Navy in 2009, he wrote his autobiography, American Sniper, published last year.

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