How should one deal with the brother who assaulted the questioner's wife, his sister-in-law, and how should the wife herself deal with him, and what is the ruling on his presence in their home?

The wife erred by informing her husband of a sin her brother had repented from, as she should have concealed it. The husband must conceal his wife's brother's (secret) and treat him kindly, and likewise the wife should treat her brother kindly and maintain ties of kinship. There is no objection to him visiting her house, but she must beware of being in seclusion with him and displaying her adornments in front of him if there is any suspicion.