BOSTON -- One of the two men who police said may be the U-30 bank robbery suspects they've been searching was arraigned in Dedham District Court Thursday after a dramatic arrest following a bank heist in Needham.

Dimitri Long, 32, of Norwood, was arrested after a hold up at the Sovereign Bank on Highland Avenue Wednesday afternoon. He was arraigned on Thursday on several charges, including armed robbery, and ordered held on $250,000 cash bail.

A second suspect, Michael Coty, 44, was caught later in Newton, FBI spokeswoman Gail Marcinkiewicz said.

Prosecutors said task force officers were following Coty, and watched him pull into the bank lot. Long went into the bank and sprinted out a short time later, prosecutors said.

Prosecutors said when Coty saw police, he drove off.

Long was armed with a pellet gun that looked like a semi-automatic hand gun, prosecutors said.

Prosecutors said Long has a lengthy criminal record which includes convictions for civil rights violations and assault with intent to kill for which he served 3 ½ years in prison.

It was not immediately clear why a task force was following Coty.

Authorities have been searching for the "U-30" or "Under 30" bank bandits, so named because in seven previous robberies, the thieves were in and out of the banks in under 30 seconds.

Seven banks in the Metrowest area of Boston have been held up in a similar manner since March. In three cases, the robber, completely disguised, would use what looked like a bomb or explosive device and demand cash, brandishing a gun. The devices, made to look like dynamite taped together, were fake.

While authorities were distracted responding to a bomb threat situation, the bandits would flee, the gunman fleeing with an accomplice. Banks in Wellesley, Needham, Newton, Dedham and Walpole were held up over the four-month period, with the robbers usually employing the same methods.

In the Needham Sovereign Bank robbery, police recovered a cell phone, gun and cash. Authorities said based on intelligence they were able to have a task force of state police and FBI agents outside the bank within moments of the hold up.

FBI agent Randy Jarvis said the number of robberies compared to last year at this time is down, but the number of armed robberies is up.