For San Diego, Armstead was more than just a top cop with 13 years in the job as assistant chief. She was an advocate for diversity, a role model for women and a respected leader in the black community.
When she earned her master's degree in criminal justice administration, she became one of the few officers on the force to hold an advanced degree.
Armstead helped develop the department's domestic-violence unit and created its first equal-employment office so workers with complaints of discrimination could be heard.
A secret to her success, in the community and as an officer, boils down to one word, said the Rev. George Stevens, a former San Diego city councilman.
"Sensitivity," Stevens said. "Rulette has it."
Armstead was sensitive to the plight of the poor neighborhoods in San Diego, he said. "And if you can be sensitive there, you can be sensitive anywhere to anybody; for one color, for all colors."
Armstead, who turns 55 Sunday, knows about low income. Her family moved to California from North Carolina when she was 14.
"We grew up in the backwoods and had no opportunity. We were very poor," she said. "I remember we all piled into a '59 Ford and came West."
The family eventually settled in an apartment at 4800 Logan Ave. in Lincoln Park, where there was no love lost between residents and police.
"It wasn't cool to like police at 4800 Logan," Armstead said.
She attended Gompers Junior High and Lincoln High during times when racial tensions boiled over in the community. She graduated from SDSU.
Afterward, applying for her first job at the county Department of Social Services, a man in the city personnel department, out of nowhere, asked her: "Hey, are you looking for a job? How about becoming a police officer?"
Armstead thought he was joking. She had never thought about being a cop.
Armstead remembers she took the application, folded it and stuck it away for several months.
Then one day she filled it out and sent it in.
"Look what happened," she said. "I've been in the same job 31 years."
During those years, Armstead gained a national reputation.
"She's one of the pioneers in law enforcement, especially where women are concerned," said Penny Harrington, founding director of the National Center for Women & Policing in Arlington, Va. The organization promotes increasing the number of women in law enforcement.
"Women police officers owe a lot to her," Harrington said.
San Diego police Officer Lori Sinclair, who works in the recruitment unit, acknowledges Armstead as a role model and mentor for women who became cops.
"In her classes at San Diego State, I've seen her actively out there, doing her part to try and recruit women students," Sinclair said.
Women officers appreciate Armstead's concern for their plight as they try to balance raising a family with graveyard shifts and child-care issues, Sinclair said.
Armstead, who is divorced, has a 34-year-old son who is district manager for a San Diego car rental company.
Among the rank and file at the San Diego Police Department, Armstead is regarded as a fighter.
"She's a fighter in the best sense of the word," said retired police Officer Matt Weathersby, who left the force in March and had worked with Armstead for three decades.
Some of that time, Armstead was battling open discrimination in the department because she was black and a woman. She struggled through a good ol' boys network where there were few women of any color.
At the time, racial tensions were roiling within the department. There were accusations of death threats against black officers and their families.
"I had a young son and a sister to support," Armstead said. "I needed a job so I just kind of rolled with the punches."
"She has broken more glass ceilings in law enforcement than anybody I've ever known," said Lansdowne, who has been a police officer for more than 40 years. "I will miss her greatly."
He has not decided who will replace her. Cheryl Meyers is now the only woman assistant chief.
The department also is losing 33-year veteran George Saldamando, who is retiring next month. A community leader in his own right, he was the second Latino to become an assistant chief.
Armstead, who earned $140,000 last year, will get a city pension of about $9,000 a month.
Among her accomplishments, Armstead is proud of opening the equal-employment office. Her first day on the job, she fielded 22 complaints, predominantly from women.
"We were considered second-class citizens. A lot of men thought we didn't belong on patrol," she said. "The women knew they were being discriminated against, and some did complain. But the tendency in those days was to kill the messenger."
Armstead did more than complain. In 1999, after she was passed over for San Diego police chief, she stunned a packed City Council meeting by publicly assailing the selection process as corrupt right in the middle of a confirmation hearing for the new chief, David Bejarano.
Armstead filed a lawsuit, contending that then-Mayor Susan Golding secretly interviewed candidates and attempted to sway the city manager. She dropped the suit.
Five years earlier, Armstead protested a decision to reassign her that would have reduced her duties as assistant chief. She went over Police Chief Jerry Sanders' head and appealed to City Manager Jack McGrory. Sanders later reversed his decision, but denied he caved in to political pressure.
Sgt. Bill Nemec, president of the San Diego Police Officers Association, said he was impressed with Armstead's intensity for the job when she supervised the domestic-violence unit when the city was creating a family justice center to deal with the problem, the first of its kind.
"The center was experiencing growing pains and she was very supportive. You could tell she cared," said Nemec, who worked at the unit then. "She was very professional and very attentive."
Armstead said she wouldn't do anything differently in a career where she often butted heads with her bosses and city executives. She refused to back down or back away.
"There were highs and lows," Armstead said. "It has been a challenging profession. We have a ways to go. In terms of numbers of women, we are backsliding, and we need more cops, period, in San Diego.
"Although we have a low crime rate, this is no longer Sleepy Hollow."
There are 305 sworn women officers now on the force of 2,000, compared to 146 when Armstead became assistant chief in 1992. The department has the least number of officers – 1.6 per 1,000 residents – of any big city in the country.
It adds up to plenty of unfinished police business, which Armstead said she would like to help resolve. But it is time to move on.
She is satisfied with her contributions.
"When I looked at myself in the mirror this morning, I was pleased with what I saw," Armstead said.
"I shouted out, 'You go, girl!' "