It all happened so quickly. Before Enjolras had even had time to react to the officer touching Kat, she had more than handled it on her own. He found himself smiling, which probably looked rather psychotic to any onlookers.
And there were onlookers. He could hear the gasp, and feel people turning to stare at what was going on. No one rushed to the officers assistance, which was indicative of the times they lived in. But back-up might arrive any minute.
Enjolras opened his mouth, surprised that his first thought was kill him. He held it in. "We should take him. He might be useful. If not, the people can decide what becomes of him," he told her.