The movie was based on Robert L. Pike's novel Mute Witness.

Bullitt takes a rather simple nugget of a story and turns it into a crime classic through the expert use of location footage, editing, music, mood and timing, not to mention the laconic, stoic performance of ultra-cool star Steve McQueen. The movie seems to have stripped away most attempts at character development or artificial suspense, and focuses almost exclusively on details. Indeed, Bullitt's (McQueen) weekend on the job isn't always exciting or action packed.

The movie is justly famous today for its famous car chase sequence, which feels fast and realistic, shot at ground level with hardly any musical enhancement; many credit the film as giving birth to the modern police movie. (The movie won an Oscar for Best Editing.) It was a huge hit in its day, but today it may move too slow for modern-day viewers.

Even though the movie "Bullitt" is known for it's legendary car chase scene, this in 1968 when everything was done for real not in a studio with computer enhanced imagery, the movie is also a very fine crime/drama straight out of todays headlines and has a very good and brainy plot too.

Senator Walter Chalmers is holding a special Senate Commission on Organized Crime in America in San Francisco and has a very important witness Johnny Ross, Pat Renella, coming from Chicago to testify. Chalmers Wants to make sure that Ross is protected from the mob who beside testifying against it has also stolen $2,000,000.00 dollars from them and they want him dead and will go to any lengths to get him.

Ross is assigned a unit from the SFPD headed by Let. Frank Bullitt, Steve McQueen, for around the clock protection at an undisclosed hotel. Just before Ross entered the hotel he made a number of Phone calls one was to a hotel in San Mateo Calif. Later back in his hotel room with Sgt. Stanton, Carl Reindel guarding him Ross slides open the lock on the door and just then two men enter the hotel room and blast both Ross and Sgt. Stanton away; at the hospital Sgt. Stanton survives but Ross dies on the operating table.

Let. Bullitt wisely decides to keep Ross' death secret from Senator Chalmers as well as the media by having Ross' body put on ice in the hospital morgue, unidentified, under a John Doe. With Ross' death kept under cover Let. Bullitt checks out Ross' phone calls, before he entered the hotel room, and finds that the call to the San Mateo hotel was to a woman who registered under the named of Dorothy Simmons. With the Senate Commission hearing the next day Bullitt begins to realize that this dead hood Johnny Ross may not the person that he seems to be.

As Let. Bullitt gets closer to the truth about the whole Ross business his life becomes endangered by the two killers, Paul Genge and Bill Hickman, who killed Johnny Ross in his hotel room. This sets the scene for the thrilling and exciting car chase that the movie is noted for. Setting him up for an ambush on a deserted San Francisco street Bullitt turns the tables on the killers by backtracking and then surprises and chases them into a hot corner. We have the two killers and Let. Bullitt flooring the gas peddle and tearing up the roads and highway in and around San Francisco and the Bay Area. The exciting car chase comes to an end when, after trying to shoot at Bullitt's car with a shotgun, the killers auto loses control and smashes into a gas station with both of the killers ending dead and burned to a crisp .

Back at the police station Bullitt starts to check out the mysterious Mrs. Simmons, the woman who Ross called before he was killed, at her hotel room in San Mateo and finds her murdered. Looking at Mrs. Simmons' luggage Let. Bullitt and the police find out that she was really a Mrs. Renick and was scheduled to leave San Francisco ,with her husband Edward, on a plane trip to Italy? whats going on here?

Checking Mrs.Renick aka Simmons husbands passport photo Bullitt realizes that Johnny Ross who was killed at the hotel room was really her husband Edward Renick a car dealer from Chicago with no mob connections. Renick must have been paid off by the real Johnny Ross, Felice Orlandi, to impersonate him with Ross taking Renick's passport and identity and checking out of the country and away from the law and the mob who were both looking for him! Ross must have also double-crossed both Renick and his wife by having them murdered.

With the real Johnny Ross now heading for the San Francisco International Airport to make his getaway Let. Frank Bullitt is the only one who has a chance to stop him and as it gets closer for Ross' flight to take off for Italy the chances of him getting caught are getting slimmer by the minute.

Terrific police/action/drama with an ending at the airport, thats as good as the great car chase seen earlier in the film, that left everyone gasping. Also good in the film is Jackie Bisset as Let. Frank Bullitt's girlfriend Cathy who had trouble accepting Frank's job as a policeman especially by seeing up front and personal, the murdered Mrs. Simmons/Renick, what that job did to him as well as what it was doing to her her by living with him.