This suspect can be ruled out because of a physical characteristic. Read the crime scene report very carefully.

The crime scene report tells us the killer adjusted the driver's seat in Evelyn's golf cart. Two police officers sat in the seat. It was too close to the gas pedal for one of them (who was 6 feet) and too far away for the other (who was 5'2"). From this, we can infer that the killer is between 5'3" to 5'11".

Examine the witness statements carefully.

Based on their witness statements, all of the suspects are between 5'3" to 5'11". There isn't a witness statement for Steve, though.

Examine the "3 Pictures of Diane". There is a man in the pictures. If you're not sure who he is, check the Saguaro Sands Newsletter.

The man in the pictures with Diane is Steve. The picture of Steve and Diane standing side by side shows Steve is much taller than Diane. Diane is 5'11" (see her witness statement), which makes Steve at least 6'0" (likely much taller). We know the killer is shorter than 6'0" (due to how Evelyn's golf cart seat was adjusted). Steve is taller than the killer, so we can rule Steve out.

Read the "To Diane" note and the Resident Database.

Steve's motive is to keep Evelyn from revealing his affair with Diane. Steve is married (see the Resident Database).