Given the task definition and input, reply with output. In this task, you will be shown a passage. You need to write a fill-in-the-gap question based on your understanding of the events that might be inferred from the passage. Your question should be answerable based on the passage and only have one correct answer. Show the gap in your question with a _ .

A second gunman from the massacre may be on the run, it emerged last night. Police and eyewitnesses are increasingly convinced that Seifeddine Rezgui had an armed accomplice during Friday’s rampage. Last night a Tunisian security source said: ‘I can’t say too much but I can say there were two terrorists. There were two gunmen.’ Police issued an alert for two suspected accomplices last night, Mohamed Bin Adbdallah and Rafikhe Taiari. They say they are conducting a manhunt for men who helped Rezgui but ‘did not participate’ in the beach killings. Three survivors – two of them retired British policemen – have come forward to insist there was a second fanatic during the attack that left 38 dead.Security sources say there were two terrorists involved in Sousse attackThree British witnesses previously claimed there was a second gunmanTunisian police have released images of two suspected accomplicesThey believe men helped Rezgui but did not 'participate' in Friday's killings

I looked to my left and saw a tall slim man in black with a gun pointing towards the ground that I now know to be _.