Updated

A man accused of fatally shooting his 1-year-old son and critically injuring the boy's half-brother in a Texas hotel has so far stymied attempts to determine what triggered the violent spree by refusing to speak with investigators, police said Wednesday.

Demond Bluntson, 36, was charged with capital murder and aggravated assault in Laredo, where police say he shot the two boys. He could face yet more charges in El Campo, some 200 miles away, where police believe he killed his girlfriend — the boys' mother — and dumped her body at a property where his father lives.

"(Bluntson) still hasn't talked to law enforcement," El Campo police Chief Terry Stanphill said. Stanphill said he had sent an investigator to Laredo, but turned him around when police there said Bluntson wasn't talking.

Stanphill said a preliminary autopsy Wednesday determined that Bluntson's 28-year-old girlfriend, Brandy Cerny, likely died of multiple gunshot wounds. He said investigators have spoken to her family.

"The family has mentioned to us that they've had an on and off relationship, their ups and downs and some tough times," the chief said.

Cerny and her sons were last seen in church Sunday in El Campo. Her father reported her missing Monday morning after she did not show up for work. On Tuesday morning, El Campo police called their counterparts in Laredo to check on a lead that the family had checked into a Laredo Holiday Inn.

Laredo police said they later determined that only Bluntson and the boys checked into the hotel.

Officers knocked on their room door about midday Tuesday and immediately heard several gunshots, including one that just missed officers through the door.

Police say when they entered the room, they found Bluntson had shot and killed his 21-month-old son, Davian, and shot and wounded Davian's half-brother, 6-year-old Jaydin. The boys' mother's body was found hours later, in a green shack hidden among trees behind a small house and a mobile home, on an El Campo property where Bluntson's father lives.

Jaydin remained on life support at a San Antonio hospital Wednesday, Laredo police spokesman Joe Baeza said.

Becky Ivy, a legal assistant in the Wharton County district attorney's office, said an investigation into Cerny's death was ongoing and that there would be no immediate comment on possible charges.

Pastor Bonny Hargrove, 47, who lives across the street from Bluntson's father, said she last saw Bluntson about two weeks ago.

"He had his head on straight. He was staying out of trouble. He seemed to be upbeat. He was a person who was determined, wanted to work and take care of his family. I can't believe this happened," said Hargrove, who added that she's lived in the neighborhood for six years and would see and talk with Bluntson and his father every so often.

Hargrove said she'd heard about the couple's relationship problems and that they were no longer living together, but "to hear him talk about his family and then to hear about this, it's still unbelievable."

"It's a horrible thing," she said.

In addition to capital murder, Bluntson also was charged in Laredo with two counts of aggravated assault with a deadly weapon against a public servant and one count of aggravated assault causing serious bodily injury, Baeza said in a statement. A judge set bond at a combined $2.5 million for the counts.