He attempts to murder Marty before being hacked to pieces by him with his own trowel. He inadvertently helps out Dana and Marty by grabbing the leg of the security guard who is sent to kill Marty, and is last seen when his dismembered arm wraps around the unconscious guard's face before his elevator cube door closes.
Judging by the way his sister speaks of him within her diary, one can say that she and her older brother are very close and that both of them feared their older brother, Matthew.
His weapon of choice is one half of a broken set of shears, however, Marty refers to it as a trowel. His weapon is also seen being used by Marty during the Purge.