The tweet, which has now since been deleted, was captured by user Fake Luke:
Luke G @LG_RoyalsBlue
Shaun Smith is having a bad day... He made his account private So I kept this to help us remember https://t.co/1z0lRUgL8Z2016-1-5 21:47:30
Smith has also made his previously verified account private. (Twitter unverifies accounts when they become nonpublic.)
The argument began after Smith expressed his opinion that the Kansas City Chiefs, one of his former teams, would defeat the Houston Texans in their matchup on Saturday for Wild Card Weekend. As angry tweets from fans came pouring in, Smith's messages grew increasingly defensive until he tweeted and then deleted the gun picture.
The South Carolina product spent nine seasons in the NFL, playing for five franchises. He last played for the Chiefs in 2012 before going unsigned the following season. Overall, he recorded 164 tackles and four sacks in his career.
Follow Tyler Conway (@jtylerconway) on Twitter.