One of four teenagers charged in the beating and stabbing of a homeless man pleaded guilty Wednesday to attempted second-degree murder.

Romel Jean-Louis, 17, who was charged as an adult, helped beat and cut a homeless man who was reading a book on a park bench, authorities said. The 2006 attack left William Teeters, 45, bleeding and bruised.

Two other teenagers — Patrick Keels, 17, and Michael Livingston, 16 — have pleaded no contest to attempted murder. Another, Bobby Callins, 18, was sentenced in October to two years in prison.