Source: Donnie Burgess / WIBC’s Donnie Burgess

INDIANAPOLIS — You may hear about a murder on the news and wonder what drove one person to take another person’s life. This is a question the police ask themselves, and sometimes they don’t have a definitive answer.

Most homicide cases solved by the Indianapolis Metropolitan Police Department so far this year list the motive as “unknown” or “dispute,” according to statistics provided by the department in its latest monthly homicide report.

IMPD said there had been 138 total homicides as of August 29. The report was prepared and dated Sunday, September 1. Ninety-two of those 138 homicides remain unsolved as of this writing, and only 46 are labeled “solved.” However, “Unknown” and “Dispute” are not the only motives for homicide listed by the department, although they dominate the numbers.

Here’s a breakdown of what IMPD considers to be the root cause of solved homicide cases this year:

• Other: 4 cases
• Unknown: 16 cases
• Argument: 13 cases
• Imprudence: 1 case
• Abuse: 1 case
• Flight: 1 case
• Combat: 1 case

IMPD does not list motives for nine other solved homicides, which were omitted from the report. Some homicides in Marion County are also not listed because IMPD says they may be investigated by a separate agency.

The “Unknown” motive statistic is usually the result of a suspect, witness, or both refusing to discuss the circumstances of the homicide. IMPD says the “Unknown” designation typically changes during the trial as the facts are presented by the prosecution and the true motive for the crime can be revealed.

The latest solved homicide case listed by IMPD is the Aug. 21 killing of George Nelson, owner of Pa & Ma’s Backyard Barbeque on Dr. Martin Luther King Jr. Street in Indy’s north side.

IMPD closed Nelson’s homicide just five days after Justin Jarvis Jones was arrested.

The motive for Nelson’s murder is listed as “an argument.”