(CNN) -

Two police officers in Indiana were killed in separate shootings in what was a violent holiday weekend in the state.

In Gary, Officer Jeffrey Westerfield, a 19-year veteran of the police department, was killed early Sunday morning while responding to a call.

It was his 47th birthday, CNN affiliate WLS reported.

The police department called the father of four's death a "senseless act of violence."

Authorities took three men in for questioning in connection with the shooting, CNN affiliate WLS reported.

A day earlier in Indianapolis, Officer Perry Renn, a 21-year veteran, was killed while responding to a call of shots fired, the city's police department said.

Renn and another officer were approaching a group of people in an alley Saturday night when a gunman shot at the officers, the department said.

Police returned fire, but Renn was fatally struck during the shootout.

"This is a sad day for the (Indianapolis Metropolitan Police Department) family and the community as a whole," IMPD Police Chief Rick Hite said.

The suspected gunman, 25-year-old Major Davis Jr., was also struck but survived. Authorities expect Davis to be charged with murder.

Davis' grandmother told CNN affiliate WISH-TV his family has had prior run-ins with police. Davis' father died of a heart attack while in police custody when Davis was a teen, the family said.

"He wasn't a bad person. His father was killed by IMPD. That is enough to hurt a person and scar him for life," Davis' grandmother, Pam Moornan, told WISH.

Police also responded to the shooting of six men and one woman in a popular bar district, Indianapolis police Lt. Chris Bailey said.

One man was in critical condition, and the others suffered nonlife-threatening injuries.

Police have not identified a suspect in that shooting, and the motive remains unclear.