Bank of America Corp. and a debt collector it hired to go after deceased customers' debts violated state law by repeatedly calling a Florida woman about paying the credit-card bill of her late husband, a Florida state-court judge ruled this month.

Judge Keith R. Kyle in Lee County, Fla., found that collection attempts by West Asset Management, an Omaha, Neb., firm working on behalf of Bank of America, amounted to harassment.

The...