The police are only treating it as serious business because it's a popular news item. (and it gets the DA's name in the papers)
s/They/The DA/
s/their/the police/
{edit} Also, the police will go after popular news items because their response will also get into the 'papers.' This way it looks to the public as if they are doing something. (The police may also feel there is public pressure to 'do something' due to the coverage of the crime.)