A 33-year-old man was being held Thursday on six counts of murder after the police said he shot four children and two adults inside a house in a Houston suburb as part of a domestic dispute.

The police said that it was not clear how the gunman, identified by the authorities as Ronald Haskell, was related to the victims, but that he was married to a relative of the homeowners, who were among those killed.

“It was a domestic situation involving a divorce, but beyond that, we’ve had no statement from him,” Ron Hickman, a Harris County constable, said.

Image Ronald Lee Haskell Credit... Harris County Sheriff's Office, via Associated Press

Mr. Hickman said that on Wednesday afternoon, Mr. Haskell drove to the relatives’ house in Spring, Tex., “gathered up the children that were here and awaited the arrival of the parents.”