Steps in a Criminal Investigation: From Crime Scene to Courtroom Arraignment

The Chronology of Law Enforcement Investigations

When an alleged crime occurs, police departments and specialized detective bureaus initiate a multi-phase investigative process designed to gather evidence, establish suspect identity, and establish probable cause necessary to support formal criminal indictment.

Phase 1: Crime Scene Securing and Evidence Collection

The first responding officers must establish physical cordons to secure the scene against contamination. Evidence technicians and forensic specialists execute systematic sweeps to log, photograph, and package physical items:

• Latent fingerprint lifting and ballistics recovery.
• Biological fluids collected for DNA profiling in CODIS.
• Digital video extraction from municipal transit cameras, doorbell surveillance, and business security systems.
• Strict maintenance of the Chain of Custody log documenting every individual who handles, transfers, or tests evidence.

Phase 2: Witness Interviews and Lineups

Detectives interview complaining witnesses and third-party observers. When identifying unknown suspects, law enforcement protocols are strictly regulated to avoid impermissibly suggestive procedures:

• Double-Blind Photo Lineups: The administering detective does not know which photo depicts the suspect, preventing subtle non-verbal cues.
• Sequential Presentation: Showing photos one at a time rather than simultaneously to ensure independent evaluations.

Phase 3: Search Warrants and Probable Cause Affidavits

To search private residences, vehicles, bank records, or mobile phones, detectives must draft a sworn Probable Cause Affidavit submitted to an independent judge or magistrate. The Fourth Amendment mandates that warrants must establish probable cause and describe with particularity the specific places to be searched and items to be seized.

Phase 4: Arrest and Booking

Once probable cause is established or an arrest warrant issues, law enforcement arrests the suspect. At the police station, booking procedures include digital fingerprinting, booking photography (mugshots), criminal history checks, and property inventorying.

Phase 5: Prosecutorial Review and Initial Arraignment

Police reports are submitted to the District Attorney or State Attorney's Office. Prosecutors determine whether to file formal misdemeanor information or seek a felony Grand Jury indictment. Within 24 to 72 hours of arrest, the defendant appears before a magistrate for initial arraignment, where charges are formally read, bail conditions are argued, and plea entries are logged.

Key Legal Next Steps

1. Request all body-worn camera footage, dispatch audio, and chain-of-custody logs through initial defense discovery.
2. Scrutinize the four corners of the police search warrant affidavit for omissions or false statements under Franks v. Delaware.
3. Retain experienced defense counsel prior to grand jury deliberations to present exculpatory evidence.