NEW You can now listen to Fox News articles! In a matter of days, authorities have revealed a trove of information about Cole Allen after he allegedly tried to assassinate President Donald Trump, while the public has learned little about Thomas Crooks nearly two years after his assassination attempt. The contrast raises new questions about transparency and what remains unknown about Crooks' shooting of Trump, and experts say the explanation may be simpler than it seems. In the latest case, investigators quickly developed a clearer picture of the suspect’s apparent grievances, communications and alleged planning. But in the Crooks case, key questions about motive and mindset have lingered long after the shooting, fueling speculation about what investigators know and why the public still knows so little. Experts who study assassination attempts and targeted violence say the difference often comes down to evidence.…