A warrant has been issued for an 87-year-old Florida woman accused of killing her disabled grandson by intentionally giving him an overdose, authorities said.

>> Read more trending news

According to Bradenton police, Lillian Parks admitted she killed Joel Parks, 30, because she feared she was dying and worried about who would care for the man, the Bradenton Herald reported.

Police said Lillian Parks will be arrested on a second-degree murder charge when she is released after undergoing a medical evaluation, WWSB reported.

Lillian Parks was the guardian for her grandson, who could not care for himself and stayed in a group home during the week, the Sarasota Herald-Tribune reported. Joel Parks stayed with his grandmother on weekends, the newspaper reported.

Joel Parks does not have a relationship with his estranged mother and his father is dead, Bradenton police Capt. Brian Thiers said at a news conference Tuesday.

Police said Joel Parks was found by his sister Sunday afternoon when she went to check on him at Lillian Parks' apartment in Bradenton, the Herald reported.

“Joel’s grandmother ... made several concerning remarks, spontaneous remarks to officers that she had purposefully overdosed him with the intent of taking his life,” Thiers said at the news conference.

Thiers said an autopsy has been completed, but a cause of death will take some time as the medical examiner's office determines what was used to kill Joel Parks, the Herald reported.

Public records show Lillian Parks is a former nurse and held a license in Tennessee from 1977 to 1983, the newspaper reported.

Thiers told the Herald that Joel Parks' disability was that he had the IQ of a child and therefore required constant supervision and care.

“This is a difficult case for our detectives, a difficult case for our agency,” Thiers told reporters Tuesday. “Partly because we do feel bad for an individual who feels that the only option is to take another human being’s life because you’re so worried about their care after you’re gone.

"But on the other hand, this is a process where it was thought out. It was planned, and she took a human life. We need to do everything we can to bring justice to his family and his friends.”