、。
How could a university professor of all people end up committing murder?
Literal
University [possessive-の] professor [even-being-ともあろう] person [subject-が], why murder-incident [object-を] caused [explanatory-の][suppositional-だろうか].
The set expression ともあろうもの is a formal rhetorical device meaning 'a person of X's standing / someone who is supposed to be X' — used to express shock that such a person would act out of character. Morphologically: と (copula/role-marker) + も (even) + ある (be) → attributive あろう modifying もの ('one who even is X'). Pairs naturally with rhetorical なぜ~のだろうか ('why on earth...?'). 事件を起こす 'cause an incident' is the standard collocation for committing a notable crime.