Al mustapha compulsorily retired

I think there may be a slight misunderstanding. Al Mustapha is a Nigerian former police officer who was accused of being involved in the murder of General Abacha's son, Hassan Abacha, in 1998. He was subsequently arrested, tried, and sentenced to death in 2017.

However, I'm not aware of any information that suggests Al Mustapha was compulsorily retired from the police force. In fact, he was still a serving police officer at the time of his arrest and trial.

If you could provide more context or clarify what you mean by "compulsorily retired", I'd be happy to try and help you further.