Confirming the arrest, Kwale OCPD Patrick Oduma said Rashid would be interrogated before he is taken to court.
“We believe he will assist detectives with information that will lead to the arrest of other key al Shabaab members on the run,” said Oduma.
The ex-officer became one of the most wanted terror suspects with his photo being circulated by police on May 30 after he was linked to the brutal murder of a chief in Kwale.
Police also believe that apart from training, Rashid was tasked with eliminating government informers.
The former GSU officer left the service 12 years ago under unclear circumstances.