No two cases are alike, but investigators share five characteristics needed to function. First and foremost is an analytical mind-set to consider multiple theories of how a crime occurred, followed by strong communications skills to deal with suspects and witnesses. A flexible outlook is also essential to coping with the job's sometimes relentless personal demands. However, these qualities are meaningless without a strong sense of integrity, particularly if alternative theories lead cases in a different direction.

Analytical Mindset

An analytical mind-set and keen sense of curiosity are important skills to develop, says Kevin Trees, a Louisville, Kentucky, detective featured on A&E TV's investigative reality show, "The First 48." Chasing leads and identifying suspects requires looking at cases from many different angles, Trees stated in a posting for the website.

Avoidance of Groupthink

Good investigators resist promoting one theory above all others. Known as "groupthink mentality," this situation is most likely to happen when fatigue and stress push investigators to their limits, former Vancouver detective inspector D. Kim Rossmo stated in an October 2009 "Police Chief" magazine article. Good detectives are flexible enough to admit their original theory is wrong because they realize that failure to acknowledge mistakes increases the likelihood for additional errors, Rossmo says.

Effective Coping Strategies

Investigators must develop ways of coping with the long hours and irregular schedules that distinguish their jobs. Detectives may be called any time, so relaxing with family and friends can be problematic, according to Trees. Even if he is not working a crime scene, Trees says, a detective must still take calls from detectives handling cases in his absence, he stated. Detectives can find that emotions spill over from investigating difficult or frustrating cases, Trees says, and their families have to deal with that.

Sense of Integrity

Investigators need a strong sense of integrity. This is especially important in avoiding wrongful convictions, which often result from ignoring alternate theories, according to Rossmo. In 1994, a British court ruled that police improperly used a covert operation to implicate Colin Stagg in the stabbing death of Rachel Nickell, Rossmo says. The outcome forced prosecutors to withdraw their case and release Stagg. Failures of integrity can damage departments' and investigators' reputations, Rossmo says.

Strong Communications Skills

Good detectives are strong communicators in dealing with suspects, according to a report written by corporate investigator Christopher D. Hoffman. Direct accusation works best when substantial proof of guilt emerges, but subtler strategies are needed for multiple suspects, Hoffman says. One variation is the Reid Technique, which evaluates a suspect's knowledge of the crime and if they are answering truthfully, according to Hoffman. Investigators adapt their responses, depending on the levels of truth or deception they encounter.