HOUSTON – A rooftop gunman who police say shot four people, killing two, is still on the loose after a Thursday-evening shooting.

The incident happened around 4:50 p.m. in the 12800 block of Eastbrook Drive, Houston Police Chief Art Acevedo said. The area is near the intersection of Maxey Road and Woodforest Boulevard.

Acevedo said two groups of people got into an argument a few days ago and decided to meet at the Eastbrook location Thursday.

When the groups started arriving, a gunman who was perched on top of a nearby roof opened fire with a high-powered rifle, according to Acevedo.

VIDEO: Surveillance video of shooting

"I'm getting tired of going to the scenes and seeing young people die. A coward decided to go on a rooftop and wait for them and gun them down as if they were deer," Acevedo said.

Four people were struck by gunfire; 20-year-old Maximo Aguilar and 18-year-old Jose Aguilar were killed. Another man was taken to an area hospital in critical condition and an 18-year-old woman was shot in the knee, Acevedo said.

"They were here to kill people. And they were going to kill as many as they could. It's probably a miracle they didn't kill all of them," nearby resident Johnny Perry said.

"I go by this park two to three times a day. I have never seen anyone using it as a park," said Beverly Campbell, another resident.

Campbell said she is concerned that the newly placed park is not used and will create a space for crime in the area.

"I can't imagine how bad it could have been and how many children are out at 4:45 (p.m.)," Campbell said.

Investigators said they're searching for a black Chevrolet Tahoe and other people who may have been involved in the deadly shooting.

Acevedo was visibly upset when he provided updates to the media. He adamantly said his department was going to find the gunman and bring them to justice.

Acevedo has a clear message for the shooter.

"Come forward now, because if we identify you first, you're going to pay the price just like the person that pulled that trigger," he said.

For the neighborhood and community, Acevedo said, police will find those responsible.

"It may not be your loved one. It may be tomorrow, unless we stand up together to stop this violence. And I promise you, we're going to find these cowards," Acevedo said.

Anyone with information is asked to call Crime Stoppers at 713-222-8477.