The police on Saturday gave a fuller account of the deadly events inside the Henry Pratt Company warehouse on Friday afternoon, and identified the five workers — all co-workers of Mr. Martin — who were killed.

The victims included some of the company’s most experienced workers but also its newest: Josh Pinkard, who was the plant manager of the warehouse, perished in the shooting, as did Trevor Wehner, who was a student at Northern Illinois University and an intern in the company’s human resources department. Mr. Wehner was expected to graduate from college in May. Friday was the first day of his internship, according to officials from Northern Illinois University.

“He knew he wanted to work in the H.R. business and was hoping this internship would lead into a full-time job in the future,” said Winter Lane, Mr. Wehner’s girlfriend of more than three years, who grew up with him in the same small town of Serena, in north central Illinois.

Everyone there knew Mr. Wehner. He was kind, the most selfless person she had ever met, she said, someone with a big smile and a personality to match. “He always saw the good in everyone,” she said.

Also killed, the police said, were Vicente Juarez, a stock room attendant and forklift operator; Clayton Parks, the human resources manager; and Russell Beyer, a mold operator. Officials at Northern Illinois said that Mr. Parks had also graduated from the university, in 2014, and that it was offering counseling help to those in need. (The school, in DeKalb, Ill., was the site of another mass shooting 11 years ago.)

Abby Parks, the wife of Clayton Parks, said he was devoted to their son, Axel, who is 8 months old. “The family we created together was Clay’s greatest joy,” she said. “He took his responsibilities as a husband and father very seriously and held those titles above all else.” The couple had been married since 2016.

The police first received several 911 calls at 1:24 p.m. on Friday, as frantic callers said there was a shooter at the warehouse. Mr. Martin had been summoned to what the police described as a “termination meeting” at the warehouse where he had worked for at least 15 years. At least two victims were shot at the scene of that meeting.