(CNN) -- Three police officers and a state trooper were shot Sunday in Midlothian, Texas, and authorities were in a standoff with a 25-year-old suspect, police said.
The situation began unfolding at 2:50 p.m. (3:50 p.m. ET), when a woman in this town 25 miles southwest of Dallas called police to report that a window in her apartment had broken without any apparent explanation, Midlothian Police Department spokesman Britton Snipes told CNN.
Investigating officers discovered it had been broken by a bullet and traced its trajectory to another apartment in the same Eastwood Apartments complex, he said. (Watch as lawmen swarm around suspect's apartment -- :49)
"On entry, they were immediately fired upon," he added.
Authorities were in negotiations with the suspect, identified as Richard Miles.
"We are negotiating with him by passing notes back and forth," Snipes said. "He doesn't have telephone service."
Snipes said authorities do not know how heavily armed the man is, but they do not believe he has any hostages.
A tactical team was on site at the apartment complex, from which some residents had been evacuated, he said. "It's going to be handled as a crisis situation."
A barrage of gunfire broke out briefly during the standoff.
The four wounded law officers were taken to Methodist Central Hospital in Dallas, he said.
The victims were identified as Dustin Compton, 30, shot once in the calf; Sgt. Brian Woolery, 34, in stable condition in the intensive care unit; and Trooper Rick Smith, who was undergoing surgery after being shot under the eye.
"He's in good condition," said Texas Department of Public Safety spokeswoman Lisa Block. "He is talking."
Another officer, 28-year-old Cody McKinney, was shot three times, but his condition was not known Sunday evening.