CHULA VISTA, Calif. -- A San Diego-area attorney was arrested Wednesday on suspicion of shooting a San Bernardino County couple at their home 20 years ago, killing the woman and severely wounding her live-in boyfriend, authorities reported.

Eric Francis Fagan, 74, was arrested at his Chula Vista residence about 7 a.m. and transported to Rancho Cucamonga, where he was booked into West Valley Detention Center on a no-bail hold, according to San Bernardino sheriff's officials.

Fagan allegedly ambushed Cathy Paternoster, 32, and 41-year-old Carl Fuerst after they arrived at their Spring Valley Lake home with their children on Oct. 11, 1989, killing the woman and leaving her domestic partner critically wounded.

The case remained unsolved for nearly two decades. Last year, a cold-case team with the San Bernardino County Sheriff's Homicide Detail reopened the investigation, conducting numerous interviews, serving search warrants in various locations and ultimately uncovering information that allegedly tied Fagan to the slaying and attempted homicide. Officials declined to disclose that evidence.

Detectives believe the suspect, who was dating the female victim's mother at the time, shot the victims in an attempt to allow his girlfriend to obtain custody of Paternoster's daughter, authorities said.

Fagan, a civil attorney, is author of several books, including a guide to Internet dating and finding one's "soul mate."