Three Teen-Agers Slain at Kearny Mesa Hotel : Crime: More than 50 calls had been placed to the room in the two days leading up to shootings.

The discovery of the bodies of three teen-agers at a Kearny Mesa hotel raised San Diego’s four-day homicide toll to 11, police said Tuesday.

An 18-year-old woman and two 19-year-old men were discovered shot in the head at 10:30 p.m. Monday by police officers, police spokesman Bill Robinson said. The officers used a pass key to enter a room at the Holiday Inn at 8110 Aero Drive.

A motive for the shootings has not been established, and there was no evidence of forced entry into the hotel room, which has led homicide detectives to believe the victims may have known their assailant, Lt. John Welter said. The names of the victims were withheld until their families could be notified.

Police have no suspects, but hotel guests saw a man flee the area immediately following the shooting, Robinson said.

Homicide detectives are now investigating the relationships between the three victims and their associates, Welter said. It was not known whether any of the victims belonged to gangs.

“We’re not ruling out drug activity. However, at this time it does not appear to be a motive,” Welter said.

The female victim rented the room on Saturday through Tuesday, a hotel employee said. Nearly 50 calls, all made by women, were placed to the room before the shooting.

In another case, a father wanted in connection with the slaying of his 18-year-old son turned himself in to authorities Tuesday, Robinson said. Nolan Paul Jackson Jr., was fatally shot in the chest at his home in the 4600 block of Thorn Street in City Heights Monday as he tried to stop his estranged parents from fighting.

The victim’s father, Nolan Paul Jackson Sr., 37, was arrested and is being held without bail on suspicion of murder and assault.

And another slaying suspect was arrested by police in connection with death of Jorge Guillen-Aguillar, 36, of San Diego, who was found fatally shot about 12:40 a.m. Sunday behind the wheel of his car, which had crashed into a parked vehicle in the 3500 block of 41st Street in City Heights.

Fidel Lopez-Mundo, 22, was detained by immigration officers on Monday as he tried to enter the United States at the Otay Mesa border crossing, Robinson said. Homicide detectives later arrested Lopez Mundo, who is being held on suspicion of murder.