A Dec. 12 hearing date has been set for three men appealing their sentences for the random robbery and killings of Mount Pleasant residents Michael and Thelma King on the island of St. Maarten.

Relatives of the couple plan to travel to the island for the appeal proceeding, which will be heard by a panel of three judges, according to Todd King, Michael King’s brother. The judges will likely issue their ruling about three weeks later, he said.

Prosecutors were not surprised by the appeals, which they have said are fairly common in such cases. Solicitor General Taco Stein was in The Netherlands and unavailable for comment Monday, but he has repeatedly expressed confidence in the prosecution’s case against the trio.

During a May court hearing in the island capital of Philipsburg, Judge Tamara Tijhuis found 29-year-old Meyshane Kemar Johnson and two other men guilty in the gruesome September 2012 killing. Johnson, the man who slit the couple’s throats, received a life prison term.

Johnson’s co-defendants, Jeremiah Chevon Mills, 18, and Jamal Jefferson Woolford, 21, received 28 years and 22 years, respectively. Testimony during the trio’s two-day trial in April indicated that Mills and Woolford played lesser roles than Johnson in the actual killings.

In August, the court granted a request from Johnson’s attorney for additional psychological testing for her client, according to The Daily Herald, an island newspaper. The lawyer, Brenda Brooks, argued that more observation was warranted due to Johnson’s past “psychotic episodes,” the newspaper reported.

Brooks did not respond to an email request for comment Monday.

Johnson, who once claimed to have chatted with a giant frog, insisted at trial that he had no recollection of Sept. 19, 2012, the night of the murders. But he and his co-defendants had earlier provided investigators with a detailed picture of what happened.

Johnson, Mills and Woolford happened upon the Kings’ Cupecoy villa and decided to rob them after committing another hold-up at a Chinese restaurant that same evening. Prosecutors said Johnson cut Michael King’s throat and stabbed him in the back and neck before cutting Thelma King’s throat while she was helpless and bound with pieces of a shredded towel.

The suspects are believed to have escaped with about $80,000 in jewelry and cash, authorities said.

Reach Glenn Smith at 937-5556 or Twitter.com/glennsmith5.