 Soon after his return to the United States , <unk> <unk> state politics , winning election to the Massachusetts Senate . He was active in the state <unk> Party organization , sitting on its secret central committee . He resumed his law practice , in which he took on as a student Daniel Webster . One of the highest profile cases he took on was the 1807 defense of Thomas <unk> , accused of murdering Charles Austin . <unk> , an older <unk> attorney , had been retained to assist in the collection of a debt from Austin 's Republican father . In the politically charged atmosphere of the day in Boston , <unk> , fearing for his own safety , had armed himself with a <unk> pistol . The younger Austin had , apparently on his own initiative , sought to beat <unk> with a cane , and <unk> fatally shot him in the encounter . <unk> was <unk> by Attorney General ( and future <unk> gubernatorial opponent ) James Sullivan , and the defense also included arch @-@ <unk> Harrison Gray <unk> . <unk> argued <unk> acted in self @-@ defense ; <unk> was acquitted of murder by a jury whose <unk> was <unk> and <unk> Paul <unk> after fifteen minutes ' <unk> . 
