BROOKLYN - Police are searching for a serial robber who has held up Brooklyn businesses four times since last month.

According to investigators, the man was caught on camera during the most recent armed robbery at a 7-Eleven on Knapp Street in Sheepshead Bay Sunday. They say that in each case, he threatens store clerks with a gun and takes off with cash.

The suspect's crime spree started April 15 at a 7-Eleven located at 133 Avenue U. Cops say he struck again three days later at a Universal Grocery on the same street, and returned to the first 7-Eleven this past Saturday.