HOUSTON -- Deputies shot a man Wednesday who is believed to have stabbed three people, including a 3-month-old baby.

The 19-year-old suspect is related to the victims, although their exact relationship is not yet known, a Harris County Sheriff's Department spokesman said.

The victims were all taken by Life Flight helicopter to Memorial Hermann Hospital in the Texas Medical Center.

The sheriff's department was at the scene Wednesday night at Tregarnon Drive at Grand Oaks Boulevard in east Harris County.

At about 8 p.m., a woman called 911 and said a man was being stabbed. When deputies arrived, they were confronted by a man with a knife, the department said.

The deputy shot the man and wounded him. He was taken to LBJ Hospital in serious condition.

Once inside the residence, deputies found the three stabbing victims: a man, a woman and the baby.

The man and woman were in critical condition and the baby was in serious condition.