Dr. Bill Lewinski and Dr. Matthew Sztajnkrycer of the Force Science Research Center recently released a scientific study conducted by researchers Dr. Brent Snook and Kathy Keating of the Memorial University of Canada. The study analyzed 90 police interviews of witnesses to assaults, sexual attacks, and homicides. The results indicated that law enforcement officers commonly use the wrong tactics during witness interviews.

Rather than adhering to the 80/20 rule of thumb in which an officer interviewer does 20 percent of the talking and the witness does 80 percent, the officers talked roughly 36 percent of the time. Some did more than 50 percent of the talking. Rather than phrasing 20 percent to 30 percent of the questions as open-ended questions, officers asked only 6 percent as open-ended questions. Specific closed-ended questions elicit only information tied to the specific question and result in no unsolicited new information.

"This approach seems to stem from the desire or notion that the officer should rigidly control the interview, treating cooperative witnesses like they're on the stand in court. That's not the optimum way to gather information," researchers noted.

In 12 percent of the interviews, the witnesses were given warnings before questioning about legal consequences for giving false information. This resulted in "significantly shorter" responses and may have hindered the establishment of rapport.

All of this is true when applied to any police witness interview and I believe most true and detrimental when applied to gang crime interviews. Witnesses to any violent crime are often reluctant to become involved but in gang neighborhoods these witnesses quickly learn that gangs hate snitches. They have read about and sometimes witnessed gang retaliation against witnesses.

In these same gang neighborhoods, there is also a general culture of mistrust towards the police and the courts. An officer, who might attempt to be very professional, impartial and in-charge, can come across as officious and stern. This does not elicit open communication.

I once accompanied an LAPD homicide detective to interview one of my informants housed in the most secure facility in the county jail. This supposedly "experienced" homicide detective who was a member of the highly touted Robbery Homicide Unit began the interview by sternly standing over the seated inmate and telling him that he didn't want any bullshit and that he was not offering or giving anything in exchange for any of the informant's information.

The informant was a many times proven reliable witness and not one to be threatened. He was a member of the Compton Lantana Block Crips and a former Black Guerrilla Family member. He calmly turned to me and asked me to return him to his cell. As I walked him out of the interview room the informant said of his interrogator, "Where did you find that SOB?" "F___ him and his mama; I wouldn't piss on him if he was on fire."

Later I would interview and document the informant's valuable information, but nothing was ever again mentioned about the LAPD robbery homicide cases. The informant gave information on other murders, a corrupt Housing Authority officer, drug dealing in the projects in South Los Angeles, and gang threats against police officers. He bought dope for the FBI and testified in federal court against the drug-dealing gang, resulting in the conviction of several major players. But he never spoke again with that LAPD detective.

In another in-custody prison gang witness interview, my co-interviewer was an LASD homicide detective. This witness was a long time San Gabriel Sangra gang member and Mexican Mafia dropout.

This LASD detective was one of the best homicide detectives I've ever worked with. He was efficient and elicited excellent information from the witness. He avoided expounding on his own theories and opinions, or asking leading questions. He allowed the witness to answer questions without interruption. In his own efficient manner, he kept the subject on track and controlled the interview.

But the Mexican Mafia informant was making me nervous. He was in top physical condition and we were unarmed and in a very isolated part of the Men's Central Jail. Fifty-some year olds, like Frank and I, would have had our hands full if this witness had decided to fight.

I remembered that when jail deputies first brought him in and uncuffed him, he seemed uncomfortable. During the interview, he quite openly gave us good information, but it seemed to me that he was holding something back.

This subject was well known to me, and I had interviewed him before. I had been impressed with his bearing. He would look you in the eyes and tell you about some gruesome murders and his own diabolical criminal thinking. This day, his eyes were furtive and he seemed uncomfortable.

Frank wasn't asking enough open-ended questions. At last, Frank had what he needed. I asked my own open-ended questions, "What's wrong?" "You holding something back?"

He finally locked his eyes with mine and paused. "I have a cuff key," he said. He pulled the jail-made cuff key from its hiding place in the gap between his teeth. "What else?' I asked. "I got a shank too," he answered. Believe me I never expected these responses.

It turned out that this informant had suspected other inmates housed in the Security Housing Unit of plotting with the Mexican Mafia to kill him. He had overheard guarded whispers about moving on him for dropping out of the EME. Since he was in a single-man cell, this could only occur while he was being moved. He fashioned a shank and a cuff key in order to be able to free and defend himself should he be attacked. The knife was keestered (hidden in the anus).

When we summoned the deputies, the witness surrendered the weapon and key. We arranged for him to be moved to another facility. Based on his suspicion a search was made of the cells surrounding his cell and other jail-made weapons were found. He was probably correct to suspect an attack.

That's the power of asking the right open-ended questions and letting your informant speak.

The Force Science Research Center suggests four categories of open-ended prompts to elicit useful and thorough responses.

      •  Descriptive: "Tell me what happened..."

      •  Casual: "What do you think brought this about..."

      •  Historical: "Give me time frames as to when and how this evolved..."

      •  Comparative: "Have you seen or experienced anything like this before..."

The responses can be further opened with the follow-up prompts such as, "Tell me some more about this."

There are many important factors in gang-crime investigation requiring detective skills such as crime scene forensics, search warrant writing and service, and just good shoe leather police work.

In my experience, the case is going to hinge on what happened in the interview room, the use of cognitive interviewing techniques, and the information you are able to glean.