In ALL United States criminal courts, the defendant MUST be provided or allowed to inspect prior to trial, ALL evidence that the government intends to use against the defendant.   This right is encompassed in the Bill of Rights, specifically in the 5th and 6th and 14th amendments of the US Constitution.  This right is essential in enabling the defendant to prepare a proper defense for crimes alleged by the government.  A defendant's right and guarantee of what is known as Due Process of Law is protected.  The material or evidence that the government must provide to the defendant is commonly known as "Discovery."

Discovery comes in many different forms.  It may be police reports, autopsy reports, ballistic reports, medical reports, DNA findings, search warrants, written statements of witnesses or suspects, documents that alert the defendant of the government's intent to use "prior bad acts' (criminal convictions that may trigger the Alabama Habitual Offender's Act), photographs, or confessions written by the defendant himself.  This type of discovery is known as "paper discovery."  Other discovery may include, surveillance video, video recordings of police interviews, body / car camera videos of law enforcement, and forensic interviews of alleged victims in sexual assault cases of minors, doorbell cameras, etc. 

Regardless of the type of discovery (evidence) involved in the prosecution of a criminal case, IF the government intends to use it in court in ANY shape, form or fashion, the defendant is entitled to possess a copy of it.  If the government FAILS to provide an item of discoverable evidence to the defendant, the defendant's lawyer must and will quickly object to the introduction of the evidence (discovery) in court.  The remedy for such an occurrence would most certainly call for the exclusion of the evidence in trial.

In some jurisdictions in Alabama, it's like pulling teeth to get the District Attorney's Office to provide discovery in a timely manner!  However, most DA's offices and municipal prosecutors are quick to provide defense counsel with the government's evidence quickly.  For example, The St. Clair County District Attorney's office in Alabama is EXTREMELY responsive to discovery requests and provide criminal defense lawyers with the discovery in criminal matters very quickly.  Lyle Harmon, the St. Clair County District Attorney, is who comes to mind immediately.  I have practiced criminal defense law in 55 of Alabama's 67 counties.  St. Clair County DA's office is the best and quickest when it comes to defendants receiving case discovery.

Obviously, the bigger the case and more serious the charge(s) against a defendant affects the time in which discovery is provided to the defendant.  The discovery process is an ongoing process but is always completed in a timely manner BEFORE a trial would ever commence.