HOW DO the police identify suspects? How do they know who to investigate? How do they know who to put under surveillance or who to arrest? These are questions many persons pose as they point to the country's unacceptably low number of arrests and convictions for crimes.

Veteran detectives note that to solve crimes, investigators may receive tips, infiltrate gangs, gather forensic evidence at crime scene and monitor emails or bank accounts.

Detective Superintendent Clinton Laing, crime officer for western Jamaica, says while first-hand accounts are critical, investigators cannot rely on this.

"Because of what is happening today, where most persons are not forthcoming with information, especially in murder cases, we have to do background checks on victims to help determine possible persons of interest and motives," Laing told The Sunday Gleaner.

Laing explained that intelligence-gathering is information that has been checked and verified and may be used for supporting evidence.

Circumstantial evidence

The police are also able to identify suspects based on the description of the perpetrator, an alias, and personal information pertaining to a place of residence or family and social ties. This information can be found in a complainant's report.

Evidence is facts presented in support of a claim, usually in a court, to establish or challenge allegations.

Shaun Wallace, criminal defence barrister based in London, England, shared that investigators also rely on circumstantial evidence to identify suspects.

"Circumstantial evidence is a set of facts, and from these facts you can draw strong indications that conclude in guilt or innocence," argued Laing.

"There are a number of factors they can use. There may be forensic evidence left at the scene; or if a crime is committed in a way similar to one committed by a certain type of criminal, then the police can narrow it down to that person," the barrister said.