The Portland Police Bureau is looking for help catching a bank robber nicknamed the "foul mouth bandit," and they're willing to pay for the assistance.

The man is suspected of robbing four banks around Portland in April, earning the nickname after using crass language as he committed the crimes.

Police describe the suspect as a black male, 30 to 49 years old, 5 feet 10 inches tall, 185 pounds, with a medium complexion, and a heavy build. He wears glasses and generally a hooded sweatshirt and baseball cap during the robberies, police said, and has implied he has a gun, though no gun has been seen in any of the crimes.

The police bureau, along with Oregon's Financial Institution Security Task Force, is offering a reward of up to $5,000 for information leading to the man's arrest.

The suspect robbed four banks around Portland last month: OnPoint Credit Union at 1720 N.W. 9th Ave. on April 3, Wells Fargo Bank at 5730 N.E. Martin Luther King Jr. Blvd. on April 4, Bank of the West at 905 N.E. Halsey St. on April 7, and Advantis Credit Union at 3515 N.E. 15th Ave. also on April 7.

Police are asking anyone with information to contact Detective Brett Hawkinson at 503-823-1080 or brett.hawkinson@portlandoregon.gov.

--Jamie Hale | jhale@oregonian.com | @HaleJamesB