Looks to me like Edward Everett Horton. He was my guess, and I checked IMDb and sure enough, he is in the cast. He appears in classics such as "The Gay Divorcee" and "Shall We Dance" with Astaire & Rogers.
Are you talking about the policeman laying on the ground under the car? That is the only character not identified in the legend on the official movie program, and my friend and I have debated who he is supposed to be for several years.
It is most definitely not E.E. Horton. He played Mr. Dinkle, the owner of the hardware store, and he is clearly depicted much farther back in the mob.