CHICAGO (CBS) — Police in the south suburbs were searching for two suspects, after one person was killed and two others were injured in a home invasion Sunday evening in Harvey.

Family members said they just finished eating dinner around 7:16 p.m., when two masked men forced their way inside their house at 228 Calumet Blvd. The men attacked the father and two brothers.

“Once they entered the residence, they were all ordered to the floor. For an unknown reason, one of the attackers began to shoot,” Harvey Deputy Police Chief Gregory Thomas said.

The gunman shot 21-year-old Deon Beamon in the back, killing him. Beamon’s father was shot in the leg, and his brother was severely beaten.

Deon Beamon (Source: Facebook)

Deon Beamon (Source: Facebook)

Detectives don’t believe the motive for the attack was robbery. They believe the family had been followed to Harvey after recently moving into the neighborhood.

“There was indications the family had been stalked and they were waiting for a moment to make entry into the house,” Thomas said.

The presumption this wasn’t random was not making neighbors feel better Monday morning.

“We have home invasions and stuff, it’ just that, oh my gosh,” neighbor Gloria Poellintz said.

Lenora King said, whether it was a targeted attack or a random crime, it’s still frightening.

“This is your neighborhood, your home,” she said.

Police said they were working with investigators from the family’s previous hometown to determine why they were targeted.

Detectives believe at least some of the attackers and victims knew each other. Police were waiting on a search warrant to help them with their hunt for the killers.