Rusten Sheskey, the police officer who authorities say shot Jacob Blake in the back on Sunday, is a seven-year veteran of the Kenosha Police Department who long aspired to a law enforcement career and once described police work as “a customer service job, and the public is our customer.”

Officer Sheskey, 31, has been put on administrative leave while Wisconsin officials investigate the confrontation caught on video in which he is seen shooting while Mr. Blake leans into the driver’s side of his car. Mr. Blake remains in stable condition in a hospital, though his family’s lawyers say he is paralyzed.

State authorities said Officer Sheskey fired his weapon seven times while holding on to Mr. Blake’s shirt during an arrest. They also said that investigators found a knife on the driver’s-side floorboard after the shooting. But a lawyer for Mr. Blake’s family, Benjamin Crump, has said that Mr. Blake did not have a knife in his hand, and that he was trying to get into his car to protect his three sons, who were in the back seat.

The Kenosha police have not released Officer Sheskey’s employment file. The only disciplinary infraction that has surfaced during his time with the department was a one-day suspension without pay in 2017 for an unspecified violation of policy related to the safe use of department vehicles.

Officer Sheskey told the newspaper that “for the most part” he had always wanted to be in law enforcement.

“What I like most is that you’re dealing with people on perhaps the worst day of their lives and you can try and help them as much as you can and make that day a little bit better,” Officer Sheskey said.

He added: “We may not be able to make a situation right, or better, but we can maybe make it a little easier for them to handle during that time.”

Azi Paybarah contributed reporting. Kitty Bennett contributed research.