The brother of the newly elected Pope Leo XIV, who made history by becoming the first American pontiff, shared his "overwhelming" reaction to the news on Thursday.

John Prevost told FOX 32 that "there are no words" to describe how proud he was of his baby brother. 

"It’s overwhelming pride, but it’s also an overwhelming responsibility, being the first American Pope from Chicago – and a relative. Frightening," Prevost said. 

Prevost said his brother’s path to pope began at a young age, having gone straight into seminary after eighth grade.

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"So, the whole high school years, college years, we didn't really know him other than the summer vacation," he said.

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Pope Leo XIV, born Robert Prevost, was a suspected frontrunner to succeed Pope Francis after his passing late last month. Prevost said he had an "inkling" his brother was in the running after hearing his description on the radio. 

"They were interviewing someone on the radio, and she said there are two likely candidates: One of the Cardinals from the Philippines, and one is a Cardinal, as a matter of fact, from the Chicago area. He was a missionary in Peru and now he’s a Cardinal in Rome," Prevost said. 

But the inkling that big things were in store for the now pope even went back decades earlier. According to Prevost, the boys' childhood neighbors predicted the younger Prevost would be the "first American pope."

"The interesting thing is way back when he was in kindergarten or first grade, there was a parent, a mom, across the street — one across the street that way and another down the street," John Prevost, told WGN on Thursday. "Both of them said he would be the first American Pope, at that age."

Prevost predicts that his brother will likely be "a second Pope Francis." 

"I think he has a strong inclination to help the poor, the disenfranchised, the people that don't have a voice because he spent so much time in Peru with the people who were impoverished," Prevost said. "So, I think she sees that need and I think he will work for that. The church has to be universal and help everyone but some people need a lot more help … I don't think he can do anything, but I think immigration is big time on his mind. He thinks the country's headed in the wrong direction there." 

Prevost said his brother will have to work hard to reunite the Catholic Church, given that "so many people have gone away" in recent years.

A Massachusetts State Police sergeant who played a key role in the investigation that led to Karen Read's original mistrial on murder charges testified Thursday that, early on, he told other authorities that John O'Keefe may have been hit in the face with a bar glass, causing injuries to his face and head.

Investigators, however, ultimately alleged that Read struck her Boston cop boyfriend with the back of her Lexus SUV and fled the scene, leaving him to die in the cold, on Jan. 29, 2022. Police arrested her on hit-and-run manslaughter charges days after she found him dead outside 34 Fairview Road in Canton, Massachusetts, and prosecutors secured an indictment for second-degree murder months later. 

Defense lawyer Alan Jackson got State Police Sgt. Yuri Bukhenik to concede on Thursday that he called the medical examiner's office and said there was a possibility that O'Keefe could have been hit in the face with a cocktail glass.

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"At 10:41 a.m., you called the medical examiner's office to inform them that Mr. O'Keefe quote, was struck in the face with a cocktail glass, or at least appeared to be, correct?" Jackson asked.

"That is in part what I advised the medical examiner's office," Bukhenik began. "Where they are, responsible for the medical portion of…"

Jackson cut him off, objecting during his own line of questioning. After a brief sidebar, Judge Beverly Cannone told the witness to do his "best" to answer the questions he was asked.

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"Did you contact the medical examiner's office at in (sic) the morning of … January 29th, 2022?" Jackson asked.

"Yes," Bukhenik replied.

"And did you state to them that there was a possibility that the decedent, John O'Keefe, was struck in the face with a cocktail glass?"

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"I don't recall my words exactly, but that sounds accurate to what I might have said," the sergeant replied.

Jackson pressed him about what he did to secure the house, a potential crime scene.

Nothing.

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Jackson also asked if key witnesses, such as fellow Boston Police Officer Brian Albert, his sister-in-law, Jennifer McCabe, and her husband, Matt McCabe, could have lied from the start about whether O'Keefe entered Albert's home at 34 Fairview Road hours before he was found dead on the front lawn.

Of those three, only Jennifer McCabe has testified as of Thursday in Read's second trial. She told jurors she saw Read's vehicle outside the house shortly after midnight but never saw either Read or O'Keefe come inside.

Outside court Thursday, where she was not speaking under oath, Read told reporters in plain words that she saw him go inside.

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"I saw him go in the house," she said.

When she was asked if she could describe the "how and when," she said no but said she has in the past and believes special prosecutor Hank Brennan may play a clip at trial.

Investigators recovered a broken glass and black straw separately from the scene, as was O'Keefe's missing sneaker, evidence that Bukhenik said supported investigators' ultimate theory that the victim had been struck by a motor vehicle.

Brennan, on direct examination, asked Bukhenik if there was a phrase about that in law enforcement circles.

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"Knocked out of your shoes," Bukhenik said.

Another component to that theory was Read's broken taillight. Brennan played Ring camera video taken from O'Keefe's driveway that showed the light was cracked when she left his house around 5 a.m. on Jan. 29, 2022.

Bukhenik said he questioned Read about the broken taillight later that morning and quoted her as saying, "I don't know how I did it last night."

O'Keefe had significant injuries to his face and head as well as cuts on his right arm by the time Bukhenik saw him at Good Samaritan hospital, he said.

Bukhenik, who moved to the U.S. from Ukraine when he was 9 and joined the Marine Corps after 9/11, is expected to return to the witness stand Friday morning when court resumes at 9 a.m. ET.