Jack Keil, the advertising executive who created and gave voice to McGruff, the cartoon hound who exhorts Americans to “take a bite out of crime,” died on Aug. 25 at his home in Westminster West, Vt. He was 94.

His death was confirmed by his daughter, Betsy Kluck-Keil, who said he had recently learned that he had pancreatic cancer.

Mr. Keil worked on ad campaigns for Toyota, Cheerios and Life Savers during his years with the New York advertising agency Dancer Fitzgerald Sample (which was acquired by Saatchi & Saatchi in the 1980s). But his most enduring work began in 1979, when he spearheaded a pro bono campaign intended to educate Americans on how they could help reduce crime.

Mr. Keil (it rhymes with “smile”) decided to try a catchy slogan delivered by an animal mascot, similar to Smokey Bear, who reminds people to prevent forest fires. He told Smithsonian magazine in 1988 that he had considered an elephant, a deer and a cougar before the catchphrase and the dog character coalesced in his mind during a trip back to New York from the West Coast.

“You can’t crush crime or defeat it altogether, but you can snap at it, nibble at it — take a bite out of crime!” he said. “And the animal that takes a bite is a dog.”

Mr. Keil took the idea to his team at Dancer and soon McGruff the Crime Dog, a lanky hound dressed in a trench coat with weary eyes and stubble, was born. Mr. Keil provided the voice, the raspy sound of a detective who had just finished a long, sleepless stakeout.

“He wasn’t vicious, not tremendously smart, maybe, but he was no wimp either,” Mr. Keil said. “He was a father figure, or possibly an uncle figure.”

The character made its debut in 1980, and the name McGruff was chosen in a national contest soon after.

At first McGruff advocated for small crime-fighting measures, like forming neighborhood watch groups, locking doors and leaving lights on to dissuade burglars. He later addressed drug abuse, gun violence, kidnapping and other crimes in public service campaigns in print, on television and on the internet. One commercial included a young Drew Barrymore.

Mr. Keil voiced most of those spots, including a brief segment with the talk show host Dick Cavett.

Dick Cavett and McGruff
Video by McGruff the Crime Dog/NCPC

McGruff still represents the National Crime Prevention Council, as the nonprofit organization that commissioned him is now known, and he remains a familiar and trusted figure, especially with children. Three studies conducted for the council by market research firms indicated that 8 out of 10 children and 9 out of 10 adults recognized him.

Communities nationwide have had more real-world contact with McGruff than with most other mascots. People costumed as the character have made personal appearances to help thousands of police departments connect with the people they protect.

A real-life McGruff met President Ronald Reagan at the White House in 1984 and appeared on the sitcom “Webster” in 1986. (Mr. Keil did not serve as the voice for either.)

He continued to voice McGruff until recently.

John Mullan Keil, who went by Jack, was born in Rochester on Dec. 30, 1922. His father, Alvin, owned a charcoal company, and his mother, the former Elizabeth Mullan, was a homemaker.

He interrupted his studies at the University of Rochester to serve as a bombardier during World War II. He returned to graduate in 1944 with a degree in economics.

After an unsuccessful attempt to forge an acting career in New York — he was passionate about music and theater — he turned to copywriting, worked for a number of advertising firms before starting at Dancer.

Mr. Keil wrote two books on creativity in a corporate setting, “The Creative Mystique: How to Manage It, Nurture It and Make It Pay” (1985) and “How to Zig in a Zagging World: Unleashing Your Hidden Creativity” (1988).

In 1950 he married Barbara Miller, who died in 2014. In addition to his daughter, he is survived by a son, Nick; a brother, Richard; five grandchildren; and a great-grandson.

Users Are Losers
Video by McGruff the Crime Dog/NCPC