Evidence is vital in murder cases
When you are facing a murder charge, you have to examine all the evidence against you so that you know exactly what you are up against. One of the things to consider is that the police officers have likely done quite a bit of investigative work to present information to the district attorney to show who committed the crime. There are several ways that they can do this.
It's said that a killer always leaves evidence at the scene. This evidence can be a cigarette butt, a fingerprint or even the distinctive patterns on the shoes the killer wore. This is because some shoes are rather exclusive, so finding a person in the area who was named as a suspect and who has that type of shoes can be a huge clue. Police officers can review the wear patterns on the tread to compare to what they found on the scene.
Small fibers, shards of glass, and other nearly microscopic evidence can also be evidence. For example, if you have a fiber on your clothing that matches the blanket the police found on the victim, you might be tied to the crime.
There is also the matter of fingerprints on shell casings. Many people don't think about this when they load a gun, but it can be a huge point in the prosecutor's claim. Another thing related to the bullet is the striation marks of any casings at the scene. Each gun's striation marks are different, so it is possible for detectives to exclude that a gun shot a specific casing, but it is just as possible for them to find that the gun in question did fire the bullet.
Your defense attorney should be able to offer you a defense strategy that takes these factors into account. Working on your defense strategy as early in the case as possible gives you time to consider the options.