That's Jack Brady, ex-Navy SEAL and Texas border patrolman-turned-tough guy P.I. Created by Robert W. Tinsley, Brady made a name for himself online, and now Tinsley has collected all eighteen Brady stories in an eBook available from Amazon.
As a Spenser fan and reader of SEAL history, I enjoyed many of these stories when they first appeared, and edited two of them for Thrilling Detective. Much the same as I feel about Spenser, I wish Bob Tinsley had written steadily all these years, but as he writes in the introduction, his output has been subject to "real life getting in the way, and, quite frankly, sloth."
On the bright side, because the Brady stories appear sporadically, they're not cookie-cutter efforts. Timing and other factors had to align for Bob to write each one, and the many zines that have published Brady stories prove the character's versatility and appeal.