The mysterious death of two Saudi Arabian sisters found bound together with duct tape on the banks of the Hudson River last year has been ruled a suicide, medical officials said on Tuesday. The official cause of death was drowning.

The bodies of Rotana Farea, 23, and her 16-year-old sister Tala were discovered along the shore of Riverside Park on October 24th. Authorities said they were fully clothed, belted together with duct tape at the waist and ankles. It was later determined that the girls had fled a shelter in Fairfax, Virginia, where they’d been placed after reporting physical abuse by family members.

According to the NYPD, the sisters had applied for asylum in the United States on those grounds, but were denied. Police speculated that they "would rather inflict harm on themselves, commit suicide" than return to Saudi Arabia, where they last lived three years ago.

The sisters disappeared from the facility in early August, and eventually arrived in New York City in September. Credit card records reviewed by the NYPD show that they ate well and stayed at high end hotels, until eventually maxing out their credit cards. They were documented on security camera footage, apparently in good health, a week before they were found dead.

It was initially believed that the sisters had jumped from the George Washington Bridge, but police later said their bodies did not show any signs of trauma.

In a statement on Tuesday, Chief Medical Examiner Dr. Barbara Sampson said, "Today, my office determined that the death of the Farea sisters was the result of suicide, in which the young women bound themselves together before descending into the Hudson River."

If someone you know exhibits warning signs of suicide: do not leave the person alone; remove any firearms, alcohol, drugs or sharp objects that could be used in a suicide attempt; and call the U.S. National Suicide Prevention Lifeline at 800-273-TALK (8255) or take the person to an emergency room or seek help from a medical or mental health professional.