In an opinion piece published by regional newspaper Sydsvenskan, he describes an "upward spiral of violence of great proportions" in the city, where police are currently dealing with 11 ongoing murder investigations and around 80 attempted murders.
However, he still feels confident, writing that Sweden's national police have sent in backup, with more investigators to come, and local and regional police have stepped up their work.
Two recent murders in particular have left investigators perplexed: the fatal shootings of a 24-year-old dentist in December and a 16-year-old student in Rosengård this month.
In both cases, there is nothing to suggest the victims were involved in any criminal activity and they had no known enemies, sparking concerns among Malmö residents of another potential serial killer in the city.
Serial shooter Peter Mangs kept Malmö in fear during a number of months in 2009-2010, targeting people of immigrant background. He was eventually convicted of two murders and eight attempted murders and sentenced to life in prison.
Police have not found anything indicating that another serial shooter could be operating in Malmö, but are investigating the trail anyway in order to be able to rule it out.
A national expert team focused on criminal profiling has been called in to help investigate this.
Sintéus described it as "one of the motives we're working on because we want to close that door" in an interview with Swedish public radio.
One of the biggest problems for the police is finding witnesses willing to talk.
In the case of the murdered 16-year-old, for example, racist threats have been directed at pupils at his school on social media next to a picture of the boy lying dead on the ground.
"They are scared. They are terrified and are wondering who's going to be shot next," a school principal told Sydsvenskan earlier this month.