First poem:
I like the rhythm of it a lot, and you definitely made the right choice putting it in all one stanza. The couplets make the poem happen in fragmented instants, each couplet another snapshot, which matches the theme of the poem well. However, there are a few points where the rhythm hitches. It's not a big deal, just one word or syllable out of place. In the second line, it's just a tad too long to fit well. You could easily fix it by altering the wording slightly to "the bullets containing malicious might", or any other way to remove a syllable but preserve your line.
Lines 3 and 4 are off by one syllable, which seems a bit odd since they're parallel lines. A slight rewording could fix this, like:
The hand holding it's calm and still
The soul wielding it aims to kill
This not only makes it flow better, but makes the action more engaging because it's a very active way to put it.
There's something wrong with the eighth line. I'm not sure how to fix it, but it really sticks out as awkwardly written so I would try to rework that line. Maybe it's because you're writing to the rhyme, so you feel forced into a sentence you're not really behind.
If I were you, I would honestly break the last line into two. Because the reader is used to the couplets and rhythm, if a line ends "the killer's face" like that, they'll stop and think about the last line, giving it more impact.
The only other thing I have to say is that two usages of "soul" is confusing and you might want to substitute something in for one of them.
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Second poem:
Honestly, this one doesn't have the charm of the first one. The first one had a nice rhythm and went along at a steady pace, while this jerks forward not like someone who's using free verse to make a point, but like someone who's using free verse to use free verse. It's hard to follow because of that. I would take your ideas for this poem and try to put it in a more readable form, thinking more about your pacing and what you're trying to accomplish with your line breaks. A line isn't broken just to be broken, it denotes the end of a thought unless there's some good reason to break at another point.
You're getting there though :)