(1) The property you asked about doesn't appear to be for sale. If you move your cursor over the upper right corner of the screen with the property description, you'll see a button called "Public Record" and the statement "This property is not currently listed for sale on Trulia." It looks like something was recently recorded in the county courthouse, possibly a foreclosure. Keep in mind that not all foreclosures are listed for sale.
(2) Regarding your question about crime, Section 689.25 F.S. (Florida Statutes) states that a homicide, suicide, or death that occurred on a property is NOT considered a material fact that must be disclosed (by an agent) in a real estate transaction. In Florida, material facts are most often things that affect the condition of the property, such as a leaky roof (even if it's been repaired).
(3) The neighbors are not bound by the same restrictions as real estate agents. Your best bet may be to talk to a few people who live near any home you're interested in.