By Breaking Celebrity News Staff

In a new letter, Joran van der Sloot complains his "rights have been constantly abused" in jail, pleads forgiveness from the family of a Peruvian women he admittedly murdered, and denies any involvement in the 2005 disappearance of an Alabama teen in Aruba.

"My rights have been constantly abused," van der Sloot wrote in a letter believed to be penned last month, and released by his attorney Max Altez. "My former lawyer promised me I would receive 15 years if I plead guilty, I did."

The convicted murderer, who has complained before during his stint in custody, wrote, "I ask God every day that Stephany's parents can find it in their heart to forgive me."

He adds he has "a history of psychological problems which were never taken into consideration" in his prosecution and sentencing.

The 24-year-old Dutchman