SAN DIEGO - A gunman carrying a bouquet of roses confronted his pregnant girlfriend at her Mission Valley workplace and shot her to death today, according to authorities.

About an hour after the mid-afternoon shooting, which left a second person superficially wounded, Roger McDowell, 34, of San Diego, called police from a City Heights apartment to say he had killed Dawna Denize Wright, 31, of San Diego, police said.

Officers took McDowell into custody about 3 p.m. at the residential complex on Towle Court, near 52nd Street.

McDowell was booked into San Diego County Jail on suspicion of murder and attempted murder.

Wright and McDowell had what witnesses described as an "on-again, off- again" relationship, according to Lt. Jeff Sferra of the San Diego Police Department's homicide unit.

McDowell entered a fourth-floor doctor's office in a business complex at 3517 Camino del Rio South about 2 p.m. and approached Wright, who worked as a receptionist for the physician, authorities said.

Seeing the flowers, Wright asked if they were for her, at which point McDowell pulled a pistol and opened fire, according to police.

Wright died at the scene. Relatives told KNSD she was three months pregnant and the suspect was the father.

The shooting also left a man with a superficial graze wound that did not require hospitalization, Sferra told reporters.

After firing four shots, the assailant, described as being in his late 30s or early 40s, calmly walked out of the building and left the area, possibly in a gray Mercury Sable or a similar-looking car, a dispatcher said.

McDowell called police and said he had just killed his girlfriend. Officers took him into custody without incident.

Patrol officers evacuated the building and searched it and the surrounding area, guns drawn, before getting word of the arrest.