By "linked" the headline means that he introduced an undercover reporter to the hitman on the understanding that he could help the reporter with a business disagreement the reporter was having. Help by murdering someone.

This is someone he's worked with and known for many years, by his own admission. Now he claims he was joking. Some people may find that hard to believe.

People that are part of right-wing groups need to start getting curb stomped

Today I learned there's a "Turning Point UK" and I'm British...