A caption on a photo that accompanied an article yesterday about the slaying of three in Silver Spring misidentified the pictured sister of one of the victims as Vivian E. Rice. (Published 3/5/93)

A 7-year-old quadriplegic boy, his mother and his nurse were found slain inside a Silver Spring house yesterday, Montgomery County police said. The child died when his respirator was disconnected; both women were shot several times, police said.

Trevor Horn; his mother, Mildred Horn, 43; and nurse Janice Saunders, 38, of Goldvein, Va., were found dead about 7:30 a.m. in the Horn family's two-story brick house in the 13500 block of Northgate Drive.

Police said Trevor, who could barely see, hear or move, was discovered in his bed, the alarm bell on his respirator still blaring, by his aunt and a neighbor. Saunders was on the floor nearby, and Mildred Horn was found in the foyer, police said.

Someone apparently entered the house through a basement window, police said. There was "moderate" disarray at the house, but no sign of robbery, said Sgt. Harry Geehreng, a police spokesman. Police said they had no suspects or motives in the slayings.

Trevor had been on a respirator since he suffered massive brain damage at Children's Hospital in Washington in 1985, according to Montgomery County court records. The family won a large settlement from the hospital in 1990, the records show.

Trevor's father, Lawrence T. Horn, a recording sound engineer who lives in Hollywood, was divorced from Mildred Horn many years ago, friends said.

The Horns were engaged in a long-running custody battle over Trevor, and on Dec. 30, Lawrence Horn was ordered to pay $16,875 in overdue child support, plus $2,000 for Mildred Horn's attorneys' fees, court records show.

Police spent much of yesterday trying to reach Lawrence Horn.

At 5:45 p.m., he returned a reporter's call to his California home. He said he was unaware of the killings and had not talked to police. When the reporter told him that his son and former wife had been slain, he began crying.

The killings apparently occurred in the early morning, based on evidence found in the house, according to a police official. Saunders, who worked a 12-hour shift, was scheduled to leave at 8 a.m., police said.

Mildred Maree "Millie" Horn, an American Airlines flight attendant with more than 20 years' service, was scheduled to work yesterday on an 8:07 a.m. flight to San Juan, Puerto Rico, said Joy Simmons, base manager for American flight services in the Washington-Baltimore area.

Simmons said Mildred Horn was a senior flight attendant who worked mainly on flights from Baltimore to the Caribbean islands and South America.

Horn's fellow flight attendants thought it was highly unusual when she failed to show up yesterday for Flight 731 to San Juan, Simmons said.

The attendants called Simmons from the plane during the flight asking, "Have you heard from Millie?"

Police said Horn was found in her nightshirt and underwear, indicating she had not yet dressed for the drive to Baltimore-Washington International Airport.

Her van, equipped with a lift for the disabled, was missing from her garage yesterday morning.

Police found it about midday, abandoned less than a mile away in the parking lot of the Layhill Square town house development, off Layhill Road.

A police investigator theorized that the killer left a car in the town house parking lot and walked to the Horn house, then drove Horn's van back to the lot after the slayings.

A police source said investigators believe that the nurse may have been killed first and that Horn, who was asleep upstairs, was shot after she came to investigate the noise.

Geehreng said Horn's sister, Vivian E. Rice, who lives a half-block away, found the bodies when she came for her routine morning check on her sister.

Trevor's twin sister, Tamielle, a third-grader at Strathmore Elementary School, had stayed overnight at Rice's house, which Rice shares with her mother, Geehreng said.

Court records show that Trevor and his twin were born 12 weeks premature on Aug. 5, 1985. Because of a condition related to underdeveloped lungs, Trevor was expected to be on a respirator permanently, the records show.

In September 1985, Trevor suffered massive brain damage while at Children's Hospital. The Horns sued the hospital in 1988 in U.S. District Court in Washington and received a settlement in March 1990, the records show.

The settlement allowed Mildred Horn to purchase the house in north Silver Spring and pay for Trevor's medical expenses. In the settlement, Trevor was awarded an annuity of $4,835 a month for life, with a 3 percent annual increase in payments, plus a lump-sum payment of $1.1 million when he turned 18, court records show.

Mildred Horn, as Trevor's trustee, was awarded $322,359. In April 1990, she purchased the Silver Spring home for $355,500, the records show.

Trevor attended Stephen Knolls School in Kensington, a public school that serves disabled students.

Rice told investigators yesterday that she noticed that the garage door was open when she arrived at her sister's house. Rice and a neighbor entered the house and found the bodies, police said.

Margaret Lake, a neighbor who lives across the street from the Horns, said she was awakened by Rice's shrieking. "I heard Millie's sister after she opened the door," Lake said. "There was this wailing over and over, just constantly wailing. It just kept going on and on."

Eugene Sprehn, who lives next-door to Horn, said he entered the Horn house after Rice called police. After finding the women's bodies, Sprehn said, he saw Trevor lying in bed, with the "respirator still running and the alarm bell blaring."

Police found muddy shoe prints outside the large brick house, located on a cul-de-sac. Police officials said they found no shell casings in the house, indicating that the killer either used a revolver or retrieved the casings before leaving.

Neighbors said they heard nothing amiss early yesterday morning in the quiet, middle-class community.

But residents said Horn and her young children were well known in the neighborhood. Horn also has a 19-year-old daughter who is a student at Howard University.

Sprehn said Mildred Horn doted on her disabled son. "She really loved the kid," he said. "He was the light of her life."

Lake said Horn often pushed the boy down the street in a wheelchair for a visit to his grandmother's house.

Staff writers Stephen Buckley and Michael York contributed to this report.