A virus infected computer systems at Newark Police Department in New Jersey last week, taking four days to clean up.
The police department said there was no evidence of any sort of data breach and that the attack "did not disrupt the delivery of emergency services to our citizens".
"Through the efforts of the city's and the division's IT, as well as assistance from the Essex County Prosecutor's Office, New Jersey State Police and federal authorities, we were quickly able to get the system cleaned and operational in four days," said a police spokesperson.
According to one report, the virus temporarily locked down the servers, blocking access to the program used to track and analyze crime data.
In accordance to police protocols, Newark reported the breach to the FBI, New Jersey state police, and the county prosecutor's office.
In the aftermath of the attack, the department has "implemented additional safeguards" to protect the network. However, the exact nature of these safeguards haven't been disclosed, in order to -- in the words of the police -- "reduce the likelihood" of future attacks or infections.
It isn't the first time that emergency services have had their systems hit by viruses: earlier this year a Los Angeles hospital had its network taken down after the servers were infected by ransomware.