Authorities are worried a recent wave of police officer shootings may not be a coincidence.

In just 24 hours, at least 11 cops were shot around the country.

The most recent incident at a fugitive's house in St. Petersburg, Fla., left two officers dead and a U.S. marshal wounded Monday. Hours earlier, an Oregon officer was critically wounded after being shot multiple times during a traffic stop.

Monday's violence followed a bloody Sunday that left an officer in Indianapolis critically wounded during a traffic stop shooting, four officers in Indianapolis wounded after a gunman opened fire in a precinct and two more officers in Washington wounded in a shootout in a Walmart parking lot.

"It's not a fluke," Richard Roberts, a spokesman for the International Union of Police Associations, told MSNBC.com. "There's a perception among officers in the field that there’s a war on cops going on."

Florida officers Tom Baitinger and Jeffrey Yaslowitz were killed Monday when agents tried to arrest 39-year-old Hydra Lacy Jr. on an aggravated battery charge. Police believe Lacy opened fire on the agents, also injuring an U.S. marshal.

Lacy, who was found dead at home following an hour-long standoff, had a long and violent criminal record including a sexual battery conviction.

In Oregon, a gunman is still on the loose after shooting officer Steven Dodds, 45, during a traffic stop Monday. Police say the gunman, driving a 1984 Dodge truck, led police on a chase after the shooting and fired several shots at officers but missed, before being stopped by spike strips and escaping on foot into a wooded area. He is described as armed and extremely dangerous.

Indianapolis Police Chief Paul Ciesielski says he believes 60-year-old Thomas Hardy is the man who shot officer David Moore twice in the face and in his chest and leg during a traffic stop Sunday, critically wounding Moore.

The Indiana Department of Correction says Hardy had a criminal history dating back to at least 1984, when he was sentenced to 13 years in prison on a burglary conviction. He was released on parole in 1990, but has been in and out of prison since then on various charges, including seven sentences for theft, one for cocaine possession and one for misdemeanor battery.

Detectives in Port Orchard, Wash., are investigating why a man ran from deputies and then opened fire in a Walmart parking lot Sunday, sparking a shootout that left him and the woman he apparently was with dead and two officers wounded.

The Kitsap County Sheriff's deputies were answering a call about a suspicious person at the store. When they located the man and tried talking to him he ran, then opened fire as the officers followed.

Both men were hit and unable to return gunfire, but a female officer arriving on the scene shot and killed the gunman, sheriff's spokesman Scott Wilson said. Authorities said it wasn't immediately known who shot the woman, who died later at a Tacoma hospital.

And in Detroit, 38-year-old Lamar D. Moore was fatally shot after opening fire at a police station, wounding the precinct commander, two sergeants and an officer the day before a family spokesman said his brother was to be sentenced in a double-homicide case.

"There's nothing in this that makes sense at all," Police Chief Ralph Godbee told reporters during a briefing on the case.

While all the shootings don’t appear to be connected, Roberts says they have one thing in common.

"We don't have any data, but there seems to be a type of criminal out there looking to thwart authority," he told the station.

According to National Law Enforcement Officers Memorial Fund, an organization that tracks police casualties, there have already been as many officer deaths in January 2011 as there were in January of last year. The organization reported that officer deaths were up 43 percent in 2010 compared to 2009.