The Island County Prosecutor’s Office is using DNA from a baby to try to prove that the mother was raped when she was a minor, according to court documents.

Prosecutors charged Armando F. Martinez, a 25-year-old Coupeville resident, with rape of a child in the third degree in Island County Superior Court on July 28.

In May 2019, an investigator with the Island County Sheriff’s Office was alerted by a state social worker that a 15-year-old girl had given birth at WhidbeyHealth Medical Center.

Martinez, who was 23 years old at the time, was identified as the father.

Under Washington state law, a person is guilty of child rape in the third degree if that person has sex with someone who is at least 14 but less than 16 years old when the perpetrator was at least 48 months older than the victim.

In this case, the victim would have been 14 years old when she became pregnant.

A report by a detective with the Island County Sheriff’s Office states that deputies were familiar with the victim’s relationship with Martinez and that she had fought with her parents over the issue.

Deputies checked on the baby, who appeared to be in good health.

The girl told investigators that Martinez was the father of the child and was named on the birth certificate, the report states.

In an interview with deputies, Martinez acknowledged that he was the baby’s father. He said he understood the age difference between him and the girl was a “problem” but that he intended to support his family, the detective’s report states.

Detectives used search warrants to obtain DNA samples from Martinez, the baby’s mother and the baby. The swabs were sent to the Washington State Crime Lab for analysis.

It took nearly two years for testing to be completed.

The DNA tests show that the probability that Martinez is the father is 99.999994 percent, according to the crime lab report.