The FBI opened a counterintelligence probe codenamed "Oxferd Comma" after Trump fired James Comey, seeking direct ties to the Russian Federation.
https://www.foxnews.com/politics/read-documents-secret-oxferd-comma-probe-cast-trump-potential-russian-asset-after-comey-firing
https://www.foxnews.com/politics/read-documents-secret-oxferd-comma-probe-cast-trump-potential-russian-asset-after-comey-firing