Slocum in the Secret Service — Jake Logan

Slocum tracks a trio of merciless marauders!

While John Slocum has taken his share of less-than-legitimate jobs in the past, he's never signed on for a stone-cold killing. Until now. Slocum's been recruited by an old friend to work for the Secret Service on a mission that is as personal as it is dangerous.
 
The brutal Carthage brothers have escaped from prison -- and the U.S. government wants them shot on sight. Slocum almost died the last time he squared off against them. But this time, he's not going to hold back in the name of the law. And justice isn't going to be handed down by any judge -- it's going to come in a hail of hot lead from the righteous guns of John Slocum…