Given the following context:

The film takes place in England in 1865. Having been grotesquely disfigured in an African voodoo ceremony for a transgression against the native populace, Sir Edward Markham is kept locked in his room by his guilt-ridden brother, Julian. Tiring of his captivity, Sir Edward plots to escape by faking his death. With the help of the crooked family lawyer, Trench, they hire witchdoctor N'Galo to concoct a drug to put Sir Edward into a deathlike trance. Before Trench has time to act, Julian finds his "dead" brother and puts him in a coffin (the title's "oblong box"). Embarrassed by his brother's appearance, Julian asks Trench to find a proxy body for Sir Edward's lying in state. Trench and N'Galo murder landlord Tom Hacket and offer his corpse to Julian. After the wake, Trench and his young companion Norton, dispose of Hacket's body in a nearby river, while Julian has Sir Edward buried. Now free of his brother, Julian marries his young fiancée, Elizabeth, while Trench, Norton and N'Galo go their separate ways.
Sir Edward is left buried alive until he is dug up by graverobbers and delivered to Dr. Newhartt. Newhartt opens the coffin and is confronted by the resurrected Sir Edward. With his first-hand knowledge of Newhartt's illegal activities, Sir Edward blackmails the doctor into sheltering him. Sir Edward then conceals his face behind a crimson hood and embarks on a vengeful killing spree.

answer the following question:

What is the profession of the man who helps dispose of the landlord's body? 

lawyer