Acevedo explained the FBI SWAT team agent breached through a window with the front of his rifle, and felt pulling on the weapon from someone inside the room.
Houston police expect to spend a few more weeks investigating the FBI shooting, Acevedo said, and its findings will be presented to prosecutors, who will decide whether to file charges against the agent.
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A Texas kidnapping victim killed during a rescue attempt was shot when he grabbed the rifle of an Federal Bureau of Investigation agent as the agent tried to enter the home where the victim was being held, police said Tuesday.
"Tragically and sadly, Mr. Valladares was right by that window and he was bound and had his hands in front of him", Acevedo said.
It wasn't until the agents were able to get inside that they allegedly realised the person who had been killed was the one they had wanted to save.
Before the victim was found being held captive at Sanchez' home, police were able to arrest the men accused of taking the victim from his home in Conroe.
The incident began when two men bursted into Valladares' home on Wednesday morning, Vallardes' son said.
The FBI seal is seen outside the headquarters building in Washington DC
The Conroe police and the Montgomery County District Attorney's office will investigate and prosecute the kidnapping and robbery at Valladares' home, Montgomery County District Attorney Brett Ligon said.
The agent was using his M4 rifle in an effort to breach a window in the back of the home off Elbert St. after another agent lost control of his breaching tool. Authorities said he was being held for ransom by people claiming they belonged to a Mexican drug cartel. "There was no lighting inside the room".
The chief discussed his department's investigation of the shooting that killed Ulises Valladares, 47, who federal agents were trying to rescue after he had been kidnapped. There is not body camera footage of the incident, he said.
"It's truly a tragedy for everyone involved", Acevedo said.
HPD's investigation of the shooting has not yet finished, Acevedo said, and any potential charges would be referred to the Harris County District Attorney's Office.
"The people that started this chain of events that led to the death of an innocent man are the people that kidnapped that man", he said.
The agent fired his weapon two times, severely injuring the man. Minutes later, all three suspects were in custody, but, to their surprise, the agents discovered that the individual shot dead was none other than Ulises Valladares, the very man they were supposed to save.
Valladares' son is now under the supervision of child protective services but his uncle is seeking custody, said Douglas Ray York, a lawyer for Ernesto Valladares, according to CNN affiliate KPRC. "You're going to shoot somebody who is an innocent victim", York said. "He's angry, he wants answers".