The documentation surrounding Marlowe’s death does not rule out murder. Marlowe’s rumored work as a spy for Elizabeth likely meant he had sensitive information that may have jeopardized one of the men present, or their employer.  Killing Marlowe efficiently erases fear of him revealing any secrets. Marlowe had government connections confirming some sort of connection between him, Poley, Skeres, and Frizer as well as providing a reason for the meeting between them. With Marlowe potentially working as a double agent, Frizer, Poley, and Skeres were either hired by the government or acted on their own and stopped Marlowe permanently. The governement then covered up the murder by creating the inquisiton. Some theories suggest Marlowe was involved with an assassination plot towards the queen. The murder theory has not been proved, however, rumors and documentation validate parts of it. 

Marlowe had been under suspicion for being an atheist and promoting violence through his writing.  He was arrested and put on bail under government surveillance until he died. With the government suspicious about Marlowe’s faith and other criminal activities such as counterfeiting coins, his death would have been an easy solution to their problems.

Screenshot of Inquisition of Christopher Marlowe's death