INDIANAPOLIS — The fatal shooting of a decorated police officer this holiday weekend and a gun battle that wounded seven people the same day in a popular nightlife district have underscored what so far has been a violent year in Indianapolis.

Mourners left flowers Sunday on the patrol car of 51-year-old Officer Perry Renn, who had been with the Indianapolis Metropolitan Police Department more than 20 years and was a recipient of the department’s Medal of Bravery.

Police said the suspect in Renn’s shooting Saturday night, 25-year-old Major Davis Jr., was armed with an assault rifle. They said officers wounded Davis when they returned gunfire in an alley after responding to a report of shots fired. He was listed in critical condition Sunday following surgery at an Indianapolis hospital and faced a preliminary charge of murder.

The nightlife district shooting occurred in the early hours Saturday, and police had not made any arrests as of Sunday evening. They said two people bumped into each other in the Broad Ripple entertainment district, apparently setting off a gun battle that left seven people wounded, one critically.

The shootings were the latest in a violent year for Indianapolis, where 72 homicides have happened in just over six months — a pace that could have 2014 rivaling 1998, when the city had its worst year on record with a total of 162 killings.