Rebecca Ann Triska

Rebecca, circa 1958; Frank Senk

  • Missing Since 09/19/1958
  • Missing From Ambridge, Pennsylvania
  • Classification Endangered Missing
  • Sex Female
  • Race White
  • Age 15 years old
  • Height and Weight 5'1, 110 pounds
  • Clothing/Jewelry Description A green cashmere sweater, black velvet slacks and black suede lace-up shoes.
  • Associated Vehicle(s) Gold and white 1957 Plymouth
  • Distinguishing Characteristics Caucasian female. Red hair, blue eyes. Rebecca has a freckled complexion. Her nickname is Becky.

Details of Disappearance

Rebecca was last seen in Ambridge, Pennsylvania on September 19, 1958. Her father gave her two dollars so she could go to a football game in New Castle, Pennsylvania. One of her friends didn't have enough money to go, however, so Rebecca and her friend went to a dance at the now-defunct Workingman's Beneficial Union instead.

Rebecca left the dance at 11:30 p.m. Some reports say she was going to catch a ride home; other state she told two friends she was going to meet another friend at the Ambridge Theater nearby.

Two boys who left the dance at the same time as Rebecca spoke to her in front of the theater. She alone at the time, but the boys saw an unidentified man, about 35 years old, nearby and he offered Rebecca a ride home. He left after the boys said he was too old to give Rebecca a ride.

At 11:45 p.m., Rebecca was seen with an unidentified man in a gold and white 1957 Plymouth at the Route 88 Drive-In Restaurant in Harmony Township, Pennsylvania, which is just a few miles from Rebecca's home in Baden, Pennsylvania. Her companion was about ten years older than her, and has never been identified. She never arrived home and has never been heard from again.

Police arrested a suspect, Frank Senk Jr., after they learned his car resembled the one Rebecca was last seen in. They found some strands of red hair and some bloodstains inside the car.

Senk said the blood was his and the hairs were probably from his three nieces who had red hair. He said he didn't know Rebecca and had nothing to do with her disappearance, but he refused to take a polygraph. He was released after his alibi was confirmed: a girl went to police and said she and Senk went to a football game the night Rebecca disappeared and they parted ways between 11:30 and 11:45 p.m.

Senk was 25 years old at the time of Rebecca's disappearance. In 1962, he was convicted in the 1961 beating death of a thirteen-year-old girl. He was sentenced to death, but this was later commuted to life in prison. He died of cancer in the 1990s, still incarcerated. Photos of him are posted with this case summary.

Rebecca was a sophomore at Ambridge High School at the time of her disappearance. She was declared legally dead in 1967. Senk remains a suspect in her disappearance; police still have the hairs from his car and plan to test them for DNA. Her disappearance remains unsolved.

Investigating Agency

  • Beaver County Detective Bureau 724-773-8576

Updated 4 times since October 12, 2004. Last updated September 11, 2014; details of disappearance updated.