The Secret Service requested a local police cruiser to be staged at the building where the shooter was perched when he attempted to assassinate former President Donald Trump, but local police were not able to provide one, according to two sources familiar with the situation.

The Secret Service was told before the rally that local police would not be able to stage the cruiser by the building, sources said.

The detail was first reported by the Washington Post.

-ABC News’ Luke Barr and Josh Margolin

Vice President Kamala Harris addressed Saturday’s shooting in Kalamazoo, Michigan, on Wednesday at her first campaign event since the assassination attempt.

"I do want to discuss briefly what happened on Saturday. Have not had a chance yet to publicly talk about it. But I will say a few words about the attempt on the life of former President Trump," Harris said.

"It was heinous, horrible and cowardly act. My husband, Doug, and I are thankful he's not seriously injured," Harris said. "As we saw what was happening, we said a prayer for his well-being and our thoughts immediately turned to Melania, who we have met, and their family. The bottom line is no one should have to fear for the safety of a loved one because they serve in public office."

"Our heart goes out to the family of Corey [Comperatore, the spectator who was shot and killed] -- a true hero who died protecting his family. And Doug and I, of course, are holding them close in our hearts," Harris said. "We are wishing those who were critically injured that day a swift and full recovery."

The two spectators shot and injured, 57-year-old David Dutch and 74-year-old James Copenhaver, remain hospitalized.

-ABC News’ Gabriella Abdul-Hakim

House Oversight Committee Chairman James Comer has subpoenaed Secret Service Director Kim Cheatle to ensure she appears at the Oversight hearing planned for Monday, July 22.

In the days since the attack, Cheatle and the Secret Service have faced heightening scrutiny for failing to prevent the incident from happening, and even calls from some to resign. Cheatle said she would not resign from her role.

-ABC News’ Will Steakin and Lauren Peller

Investigators have found that Thomas Matthew Crooks, the 20-year-old gunman, was a loner without friends and was described as "odd," according to multiple sources briefed on the investigation.

Crooks had been "bullied" a little, "but not over the top," one source said.

Analysts are trying to assess whether he was hard to get close to or was shut off because he was hiding something, sources said.

Investigators haven’t found any helpful information on Crooks’ phone or computer and are looking to see if he may have used "burners" or other devices, sources said.

-ABC News’ Pierre Thomas and Josh Margolin