For 24 years, the person responsible for the death of 25-year-old Regina Rowe-Hicks managed to evade the reach of the law. Last year, the case saw a breakthrough when a key witness, Steve Gates, a former friend of the accused, decided to break his silence. Now, according to PEOPLE, he has given an interview with Dateline to explain why it took him so long to step forward. Regina was last seen in October 2001, when she was expected to pick up her…