How to report a Twitter user
You must be logged into Twitter to report an account.
Click the gear icon next to the Follow button at the top of the offending user's page
Click Report in the drop-down
Specify the problem with the user, in this case They're being abusive or harmful
Specify how the user is being problematic, in this case Engaging in harassment or violence
Specify who the user is targeting, in this case Someone else
Specify how the user is targeting them, in this case Being disrespectful or offensive
The user has now been reported, and Twitter presents the options to block content and/or contact from them until the report has been reviewed
Click Done to leave the reporting interface
Remember to add your reported item to Fight Against Hate so we can monitor the time taken by Twitter to remove the content.