a new report reveals the boston marathon bombers showed a lack of ` weapons discipline ' during two firefights with the brothers , a new report reveals .
in the first standoff , the officers fired ` toward the vicinity ' of tamerlan and dzhokhar tsarnaev ` without necessarily having identified and lined up their target ' , the 130-page document states .
they also reportedly failed to appropriately aim their guns .
amid their chaotic shooting , transit cop richard donohue was critically wounded .