Houston shooting today tragically ended in the deaths of six people who were reported to be family members of the gunman. The suspect for the Houston shooting today and who killed two adults, four children and injured one had tied up his victims and shot each one in the head, prosecutors said Thursday.

According to the Harris County Sheriff's Office, the suspect for the Houston shooting today was identified as 33-year-old Ronald Lee Haskell. Haskell was booked Thursday on the charge of capital murder/multiple murders and was held without bond.

Police said the Houston shooting today began when Haskell arrived at the victims' home pretending to be a FedEx employee as he was wearing the company uniform. When Haskell gained access inside the home, he reportedly gathered the children and waited for the parents to arrive. When the parents arrived, he shot all of them and instantly killed the six while one girl survived.

Harris County Precinct 4 Constable Ron Hickman detailed the events of the Houston shooting today and said, 'He came to this location yesterday afternoon ... and came under the guise of a FedEx driver wearing a FedEx shirt. (He) gathered up the children that were here and awaited the arrival of the parents. Sometime later the victims were shot in this residence, and we now learned that Mr. Haskell was married to a relative of the residents of this home.'

In a report by the Associated Press of the Houston shooting today, detectives reportedly said Haskell knocked on the front door of the home at first. A 15-year-old girl, the survivor, answered the door and Haskell asked for the girls' parents. When the girl told him they were not home, he left.

When Haskell went back moments later was when the Houston shooting today proceeded. According to KHOU-TV, when Haskell came back, he once again asked for the girls' parents, but this time he told her his name. When the girl recognized him as her ex-uncle, she reportedly tried to close the door but he was able to kick it and he let himself in, said detectives.

The dead from the Houston shooting today have been identified by authorities as 39-year-old Stephen Stay, 33-year-old Katie Stay, their two boys aged 4 and 14 and two girls aged 7 and 9.

When Haskell was inside, he demanded to know the whereabouts of Katie Stay's sister, his ex-wife, Melanie.

According to USA Today, Haskell, the suspect of the Houston shooting today already had previous run-ins with law enforcement in Utah, where he used to live with his former wife. Neighbors were apparently also aware of the condition of Haskell's marriage. The marriage was reportedly rocky that Katie Stay decided to leave for Utah to help her sister Melanie escape the clutches of Haskell and begin life anew in Texas.

It turns out that in 2008, Haskell had previously been jailed in Utah on assault and domestic violence charges.

Captain Tyson Budge of Logan City (Utah) Police said, 'She alleged that he had dragged her by her hair, out of the bedroom, and assaulted her hitting her in the head.'

In October 2013, Haskell's ex-wife filed a protective order against him. However, the charges were later dismissed as the couple filed for divorce which was finalized Feb. 14, online court records show.

The protective order was dismissed when the couple agreed to a mutual restraining order in the divorce which also involved custody arrangements with their children. According to an NBC report, the judge also said that Haskell's visits would be also be supervised by a psychologist.

Texas authorities are still uncertain whether the divorce had been completed, but they found that Haskell's previous address was in San Diego, where he used to work for a contractor employed by FedEx in January.

During Haskell's first court appearance Thursday for the Houston shooting today, prosecutor Nathan Moss said Haskell tied each family member before placing them face down on the floor, after which he shot each of them in the head execution style.

According to the Los Angeles Times, details of Haskell's relationship to the family have not been released as of the moment, but the adults killed were found to be the children's parents.

The 15-year-old girl suffered a bullet fracture to her skull, said deputies. Apparently, the girl who was the only survivor in the Houston shooting today played dead until Haskell left. She alerted authorities after he left and told them he was on his way to her grandparents to kill more relatives.

After the Houston shooting today in the suburban neighbourhood, Haskell was arrested Thursday after a standoff between deputies and Haskell in a cul-de-sac in a nearby neighborhood. SWAT officers reportedly used armored vehicles to trap Haskell. Haskell surrendered after nearly three hours of officers pursuing him through Spring, Texas.

Deputy Thomas Gilliland described the standoff after the Houston shooting today as "two hours of constant talking with a man armed with a pistol to his head and who had just killed six people." According to Gilliland, Haskell was a man in his 30s with a beard "and cool as a cucumber." Haskell reportedly appeared to be "just sitting in his car looking out at us" when the officers first approached him.

Meanwhile, as of late Wednesday, Gilliland said that the sole survivor from the Houston shooting today was in "very critical condition" at the Memorial Hermann Hospital in Houston.

Jim Sumner, chief deputy of Harris County Constable Precinct 4, told the Los Angeles Times on Thursday, 'It's a horrible situation. It's the worst thing I've seen in a long, long time. I've seen multiple homicides. But that many innocent persons is pretty horrific.'

FedEX officials also released a statement Thursday regarding the Houston shooting today and said they are extending their condolences to "all those involved in this tragic incident." The statement also stated that Haskell formerly "provided service for FedEx, but has not done so since January."

By late Thursday, police are still investigating the Houston shooting today whilst trying to piece together the life of Haskell as the man has refused to talk to authorities. Authorities said they believed that Haskell's disintegrating family situation may be the cause for the tragic Houston shooting today.

Authorities also praised the 15-year-old girl, the sole survivor from the terrible tragedy that is the Houston shooting today. They called her a heroine for trying to keep her former uncle out of the house and for directing authorities to her other relatives despite her critical injuries.

Sumner said, 'The girl is considered a heroine. She supplied officers with information and helped when the officers actually got there.'

Authorities arrived about 6 p.m. after she told them the shooter was headed for the home of her other relatives.

The teenage heroine of the Houston shooting today still remained in critical condition Thursday, but her maternal grandfather, Roger Lyon, who identified the girl as Cassidy, said she would recover. The grandfather also called her for her courage after the Houston shooting today and described her survival as a miracle.

Lyon said in a statement regarding the Houston shooting today, 'We are shocked and devastated by this tragedy that has taken these precious souls away from us.' Lyon also asked for the family's privacy and thanked everyone who sent prayers and well-wishes after the tragic Houston shooting today.

He said, 'We send our unending gratitude to law enforcement and first responders whose quick actions saved many lives. Cassidy Stay, 15, who survived the attack, is expected to make a full recovery. We are grateful for this miracle. We are in awe of her bravery and courage in calling 911, an act that is likely to have saved all of our lives. She is our hero. More information will be forthcoming in the days ahead about her heroics, but right now we want to concentrate on getting her well.'

Houston shooting today suspect, Haskell is scheduled for an arraignment Friday on the charge of multiple murder.