I look at it this way.
Luster has raped 90 or more women. However being a millionaire allowed him to hide in plain sight due to corrupt mexican cops. Chapman did the job they were too corrupt to do.
I'm sure there are plenty of murderers, rapists, and child molesters cheering for the arrest of Chapman. At least we know we don't stand in agreement with the scum of the earth who cheer a good man's arrest.
And if Chapman had been covicted and sent to a Mexican jail for capturing the scumbag Luster, there would have been publicity and Chapman probably would truly be hailed as a hero and released, but Chapman gave the Mexican judicial system an excuse to go after him with his own hypocritical and cowardly deed of jumping bail.
I found no evidence that he was 'hiding in plain site' -- Dog tracked him down to get a reward on the million-dollar bail. When Dog tried to take him, Dog was arrested in Mexico.
The Mexican authorities, upon finding out who Luster was, had him expelled back to the U.S., where he was imprisoned.
There is no evidence the Mexican authorities were helping Luster, or would refuse to send him back to the U.S.