A man involved in a domestic dispute opened fire at a suburban home near Houston killing six people, four of them children.
The victims were shot dead at the house in Spring, before a three hour stand off in which armed officers cornered a silver car containing the suspected gunman.
The Harris County Sheriff's Office confirmed that officers attended a property in Spring at around 6pm and found two adults and three children dead.
Another child later died while being airlifted to hospital. A 15-year-old girl was wounded, but survived the attack.
A woman who survived the incident, identified the shooter and directed deputies to him.
The silver car was cornered by a large police truck and a second armoured vehicle, as armed marksmen stood by.
The suspect remained in the car for three hours as officers talked to him.
Police said the suspect remained "cool as a cucumber" and after lengthy negotiations he emerged from the vehicle with his hands raised, sinking to his knees before being arrested and detained.
Assistant Chief Deputy Constable Mark Herman said: "It appears this stems from a domestic issue with a breakup in the family from what our witness has told us."
Sergeant Thomas Gilliland described the man as in his 30s with a beard. He said that when he and other officers approached, the man was "just sitting in his car looking out at us".
The identities of the victims and the suspect have not been revealed.