Freddy Patel, a former Home Office pathologist, has been condemned by a General Medical Council (GMC) disciplinary panel.
The panel investigated Patel’s reports into the death of sex worker Sally White in 2002.
Sally White was murdered, but Patel decided she had died of natural causes.
His reports discouraged a police investigation that might have saved two other women.
Patel previously found that Ian Tomlinson died of coronary heart disease after being struck by police during the G20 protests in 2009.
Two other pathologists later concluded that Ian died of internal bleeding as a result of blunt force trauma, in combination with cirrhosis of the liver.
Patel is banned from working until the end of this month.
He could be struck off.