Cologne (dpa / lnw) - After a knife attack on a homeless man in Cologne, the police arrested a 15-year-old youth. The police said on Friday that he was suspected of attacking the 50-year-old in the course of an argument and injuring him life-threateningly. The public prosecutor's office has requested an arrest warrant for attempted manslaughter. The background to the crime on Thursday is still unclear. The victim is now out of danger.