Pc Neil Tong was dismissed without notice at the end of a three-day hearing held by the force after he was found to have recorded several clips of the woman in her Walsall home and shared shared them via the Snapchat messaging app.
The clips were of a derogatory nature and some showed objects being thrown at her.
Some of the clips were annotated with a ‘crying with laughter’ emoji and sent in Snapchat messages to a member of the public and a colleague.
An independent disciplinary panel found that Pc Tong had breached professional standards relating to respect and courtesy, duties and responsibilities, and discreditable conduct.
Independent Office for Police Conduct (IOPC) West Midlands Regional Director Derrick Campbell said: “Police officers are trusted to uphold professional standards of behaviour, especially when they come into contact with people who are deemed vulnerable.
“The degrading manner in which Pc Tong mocked and otherwise treated the woman concerned was disgraceful and a clear abuse of his position of trust.
“Our investigation concluded that Pc Tong had a case to answer for gross misconduct.
“The force agreed and arranged for the officer to appear before an independent disciplinary panel which concluded that his actions did amount to gross misconduct and that instant dismissal was the only option in these circumstances.”
His dismissal on Thursday follows an investigation by the Independent Office for Police Conduct.
The investigation, which began in October 2016 and concluded in August 2017, saw video footage discovered after Pc Tong’s mobile was seized in connection with a separate matter.