There are no loopholes. If a murderer walks away free, regardless of being guilty, it's because someone made a huge mistake. A cop wiretapping someone without permission to do so for example.
And that warrants him walking free? If there is a process mistake by some dufus it warrants a killer that murdered 7 families 3 cats 1 dog walk free and you would be ok with it?
If you had a choice between overlooking this mistake done by lazy or stupid person in how the killer was caught or how the pre trial material was gathered and to point it out in the trial so that this serial killer (who told you he killed them and will kill again once he gets out) could walk free instead of sitting in jail you would choose to be 100% professional lawyer and defend the guy?
I know this is hypothetical situation but you said you would let the killer walk just because of some processes and beuracracy, I don't get that.
I'm actually wasn't talking murder in the first place, there are many things that can be done through loopholes while destroying property, hard work of other people.