Montgomery, Ala. ? A sheriff’s deputy who was cleaning a basement storage room stumbled upon a box containing a trove of artifacts from the civil rights era, including black-and-white mug shots of Rosa Parks and a young Martin Luther King Jr.

Historians called the discovery a significant find that provides a one-of-a-kind time capsule into the early days of the civil rights struggle. The 1956 mug shot of King after being arrested in the historic Montgomery bus boycott could be a record of his very first arrest, said Horace Huntley, director of the Oral History Project at the Birmingham Civil Rights Institute.

“I think that is a tremendous find,” Huntley said. “It gives us a window to the past that we absolutely would not see otherwise.”

The mug shots were in albums that were segregated by race and gender. About midway through a book marked “Negro Male” that spans from 1948 to 1965 are mug shots of King, famed civil rights attorney Fred Gray and others.

The mug shot of King depicts the intense determination he relied on to spearhead the civil rights movement. Above his stare is written in blue ink, “Dead 4-4-68,” the date he was assassinated in Memphis, Tenn. King is dressed in a jacket and tie and wearing a slate around his neck with his arrest number 7089.

In another book for black women, Rosa Parks also holds a slate with her arrest number, 7053, and gazes at the camera in a manner suggesting she had been booked before. It was her arrest nearly three months earlier for refusing to give up her seat on a city bus that sparked the boycott and, to a large degree, the greater civil rights movement.

King and Parks were among the dozens of people arrested in the Feb. 22, 1956, boycott. An accompanying jail log lists all 76 people arrested on a grand jury indictment for violating Alabama’s anti-boycott law.

“This is the first time we’ve found something like this since I’ve been here,” said Montgomery County Chief Deputy Derrick Cunningham, who made the lucky find last week while performing house-cleaning duties at the Sheriff’s Department. “And trust me, I’ve been looking hard, I’ve been looking long. To be able to come across this type of information, it means a lot.”

For Cunningham, who is black, the documents are personally significant as well.

“A lot of those people paved the way for us to ride around and be deputies,” he said. “They stood up for the rights of people sitting on the bus. They stood up for the rights of people to get jobs.”