Family and supporters have gathered in Birmingham to demand a full inquiry into the death of Kingsley Burrell - after an inquest last week found that neglect from police and hospital staff played a part in his death.
The 29-year-old died of a heart attack three days after dialling 999 for police help because he felt he was about to be attacked by a gang while he was out walking with his young son.
But he was himself detained under the Mental Health Act, transferred to a mental health unit and then the Queen Elizabeth Hospital in Birmingham before he died.
Kingsley Burrell's sister Kadisha Brown-Burrell added: "I had a meeting with the MP yesterday Shabana Mahmood, and she's looking into drafting certain letters to certain officials as well."
The services involved say lessons have been learnt from what happened.
Following the death of Kingsley Burrell, four serving West Midlands Police officers were subject to an IPCC investigation, which has recommended disciplinary proceedings. The four officers continue to fulfil policing duties outside of the evidential chain. A misconduct hearing is fixed for the end of June.