The cyber attack was launched via email and targeted multiple computer users in the St. Louis police department, although only one machine was compromised, said the police in a statement. 

Twenty-two of the potential victims of the attack were either witnesses, property owners or victims involved in criminal incidents. The other two were suspects. Information compromised may have included names, addresses, and Social Security numbers.

"The cyber attack did not affect the departments police report writing program, financial programs or the program that stores mugshots and criminal records," the department said. "The department is evaluating internal system to determine if additional measures can be taken to prevent such an attack in the future."

The department is also purchasing each of the victims one year of credit protection services from Experian, at a total cost of $2865.60.

The attack, which occurred between February 4 and February 5, might also have compromised the personal information of some department employees, including names and phone numbers.

Just last month, the West Memphis Police Department reported that a police officer was suspected of accessing fellow officers' personal information. And last year, the New York City Police Department had tapes stolen containing the Social Security numbers and pension information of 80 000 people.