Remember "In a play cast in hell there are no angels" and "There are no swans swimming in a cesspool." Don't be too disappointed by the actions of your witnesses, who will remain true to their gang culture by seeking street vengeance and refusing to help you.
Familiarize yourself with the victim's history and the history of the victim's gang and likely suspect gangs. Learn as much as you can about each gang's most active members. Don't be surprised if your victim's history is as bad as or worse than your suspects'. Remember the homicide code; he was a human being and deserves your best skills in doing your job.
No parent should have to bury their child, and often the victim leaves behind a wife and children. These family members bear little or no guilt for the crimes of the gang. Endeavor to be sympathetic and establish a working rapport with the victim's family. Often it will be these family members who will first hear rumors about who was involved and why. Your positive rapport may convince them to share these rumors with you.
Attend patrol briefings and give the patrol officers the general facts on the murder, remembering to exclude the agreed upon details. A personal appearance gives them a face and a person to identify with this investigation. Give them your contact information, offer some kind of small reward like for anyone bringing in significant leads or witnesses. I often offered a "six pack" bounty for information or an arrest when the suspect was identified.
Use these patrol officers, the gang or special projects units, station narco units, and any other support units to apply directed pressure on the target gangs. Keep these units interested and involved in the investigation. Be seen in the station often and continue your appearances at briefings.
Some gang homicide investigators monitor and interview recent station bookings each day. Some investigators let support personnel do this. Either way you need to fish for information from the new inmates; desperate people sometimes do desperate things. But beware of informants with false information. Caution should also be exercised in the use of criminal and jailhouse informants. Criminal informants are best used to produce leads and to identify other witnesses. Some criminal convictions have been reversed because of the tainted testimony of criminal informants. Unfortunately, there is often no other choice but to use criminal informants in gang homicide cases. Just be sure to corroborate and verify any informant's statements whenever possible.
If you are having difficulty obtaining information, you might consider offering a public reward. There are now many government and private organizations that can assist you in establishing a reward. When possible utilize organizations like "We Tip" and "America's Most Wanted" to generate leads.
Identifying the Suspects
Your bulldog persistence will eventually produce a suspect. This is often only a nickname at first. To get a real name, you're going to have to dig. Revisit your victim and suspect gang areas looking for graffiti with the suspect's moniker. Review your prior notes and photographs for this name. Identify and obtain photographs of your suspect and the associated names. Gang members often do their criminal acts in the company of their closest homeboys, especially the members of their sub-group or clique, and they often write these names along with their own in their graffiti.
Review the history and other information you have compiled on the gangs involved. Conduct a complete computer background check and review any other information you might have about your suspect before you decide to arrest him.
Making the Arrest
Get that especially helpful patrol unit or support unit to help find and arrest your suspect. Another option is to obtain an arrest warrant. Make sure that the arrest team includes that helpful support unit when you serve the warrant.
Attempt to interview the suspect in a non-custodial environment before making your arrest. When the suspect gives false statements, document the lies and disprove the alibis. This is almost as good as a confession because it is circumstantial evidence of a suspect's guilt.
In the initial arrest situation you will have the suspect or suspects at a disadvantage. They have not yet had time to prepare a false story, and they are anxious to divert suspicion. They will usually make spontaneous statements. Be sure to separate and interview all potential witnesses individually.
Family members may also give information identifying the suspect's close associates and his access to vehicles and weapons. If the suspect has fled they may know of girlfriends and safe houses to which he might have run. Reminding the family members that the homicide investigator's role includes the elimination of possible suspects sometimes is beneficial because they believe that the suspect is innocent.