Houston Police Chief Art Acevedo on Tuesday warned his officers to wear additional body armor on patrol, days after a police sergeant was fatally shot and his bulletproof vest failed to protect him.

Sgt. Christopher Brewster, 32, was shot and killed while responding to a domestic violence call in Magnolia Park Saturday evening. A dying Brewster radioed in a description of the gunman, and police arrested 25-year-old Arturo Solis later that evening. He has been charged with capital murder.

On Monday, Acevedo issued a memo noting that Brewster’s armor “was potentially penetrated by one or more” bullets. Investigators are trying to determine if Solis used armor-piercing bullets or if the officer’s vest was defective, Acevedo said.

“We have concerns about 2 to 3 potential defects, in terms of penetration,” he said.

Acevedo’s warning came as Brewster’s family, the law-enforcement community and the city prepared to lay to rest the nine-year veteran, a popular officer remembered for his devotion to his family and job as well as his positive attitude and sense of humor. A visitation is planned for Wednesday, followed by a public funeral on Thursday.

The chief continued to field questions Tuesday about his sharp criticism a day earlier of Senate Republicans for failing to close the so-called “boyfriend loophole” that allows those with a history of dating violence to legally purchase firearms, in some cases. He accused Texas’ two senators of caving to opposition from the National Rifle Association by not voting to pass a House-approved reauthorization of the Violence Against Women Act, or VAWA.

Those comments, which drew national attention, angered some rank-and-file officers, who accused the chief of politicizing Brewster’s death. Meanwhile, Senate Republicans pushed back on Acevedo’s claims that a federal loophole allowed Solis to buy the firearms that police found when they arrested him.

Acevedo stressed that the last few days have been highly emotional for the department.

“My officers are not a serial number to me, they’re not a badge number,” he said. “When they go down, I get pissed. If you can’t figure out why I’m pissed, shame on you.”

For subscribers: Slain Houston police sergeant Chris Brewster remembered for his friendly manner, heroism

But police officials on Tuesday were most concerned about officer safety given the circumstances surrounding Brewster’s death.

HPD patrol officers typically wear soft body armor designed to stop ammunition from most handguns and shotguns. This is the armor that Brewster was wearing the night he died. Police recovered two handguns when they arrested Solis: a 9mm Glock, and a 9mm Smith & Wesson, according to a law enforcement source familiar with the investigation.

The vests have a five-year lifespan. Brewster’s was three years old, Acevedo said.

The department has also equipped officers in recent years with heavier armor for use in active shooter situations. That armor uses hard ceramic plates — and is designed to stop rifle rounds — but is heavier and covers a smaller area than the flexible soft armor.

In the hours after Brewster’s slaying, conflicting accounts about whether he was wearing a vest sparked confusion. The chief initially said Brewster wasn’t wearing a vest, then later said he was struck “too high” to be protected by one.

After it emerged that Brewster was wearing a vest but that it didn’t work properly, investigators tested other vests from the same lot as the one Brewster was wearing, without issue, the chief said. They are also reviewing the ammunition that was used, to see if it was designed to pierce body armor.

Still, Acevedo urged officers to wear heavy vests over the soft armor for the time being while out on the street.

“The collective safety of the men and women we lead is of utmost concern,” Acevedo said in a message to officers.

In a post on social media, Houston Police Officers’ Union President Joe Gamaldi said the organization did not believe the problem was “systemic,” but also urged officers to wear both types of armor.

“Safety of our officers is our top priority,” he wrote. “Please wear your heavy vest until this issue can be sorted out. We realize this can be a bit uncomfortable for an 8-hour shift but precautions must be taken.”

For subscribers: Details into officer’s slaying emerge as Acevedo seeks law to bar abusers from owning guns

Questions also remain about how the alleged shooter, who has previous convictions for domestic violence and who relatives said has a history of mental illness, was able to obtain his firearms in the first place.

On Monday, Acevedo challenged Republican senators to pass legislation that would bar abusers from owning a firearm. He singled out Senate Majority Leader Mitch McConnell and Texas Sens. John Cornyn and Ted Cruz for criticism.

“I don’t want to hear about how much they support law enforcement,” Acevedo told reporters on the day Brewster’s body was escorted to the funeral home.

A day later, Cruz and Cornyn shot back that the issue is more complicated than the police chief initially portrayed it.

Court records show Solis had a prior family-violence conviction, which should have blocked him from legally possessing a firearm. His family and defense attorney also claim he has a history of mental illness, which also could have barred him from legally buying a gun.

“It's unfortunate the chief of police in Houston seems more focused on trying to advance his own political ambitions than on supporting the brave men and women of HPD,” Cruz said in a written statement. “The fact is that this killer was a criminal whom federal law already prohibited from having a gun.”

The Houston police union blasted Acevedo for “hijacking” a “somber moment.”

“The fact that Chief Acevedo chose that moment to make a political statement on guns, is nothing short of offensive and inappropriate,” said a memo posted Monday to the union’s Facebook page. “There is a time and place for every discussion and this was neither the time nor the place.”

Acevedo stood by his comments Tuesday and said he was “not going to engage in a back and forth” with the senators.

“My comments about the issue of domestic violence and gun violence and the context of their meaning are quite clear when viewed in their totality,” he said.

Later Tuesday, he acknowledged that his emotions “got the best of (him),” adding, “I’m not sure that maybe it was not the time. But I had a lot of anger, and the anger is still here.”

Related: Acevedo calls out Cornyn, Cruz, McConnell after HPD sergeant is fatally shot by ‘domestic abuser’

Under federal law, those convicted of assault against family members are barred from buying guns — but the law only applies to abusers who were married to their partners, lived with them or had children with them. That law does not apply to romantic partners who are not living with the victim.

Congressional Democrats earlier this year passed a version of the Violence Against Women Act that would have closed that so-called “boyfriend loophole.” The NRA, however, opposed it, and negotiations on the legislation broke down in the Senate.

It appears, however, that the boyfriend loophole did not apply to Solis.

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In August 2015, he pleaded guilty to a misdemeanor charge that he assaulted a woman he was dating who lived with him at the time, according to charging documents.

That alone should have prevented Solis from buying a gun under state and federal law. Texas law prohibits convicted abusers from buying guns within five years after the end of their punishment. Solis was sentenced to 70 days in jail.

“What matters under federal and state law is that he lived with the family member he was previously convicted of assaulting at the time of the crime,” a Cornyn spokesman said.

A visitation for Brewster will take place from 5 to 8 p.m. Wednesday at Sagemont Church at 11300 South Sam Houston Parkway East in Houston. A public funeral is scheduled for 10 a.m. Thursday at Grace Church Houston at 14505 Gulf Freeway.

ben.wermund@chron.com

st.john.smith@chron.com