At 6:27 local time, Marvin Wilson was executed in Texas. The Supreme Court denied on Tuesday a stay of the execution on the grounds that Wilson was mentally retarded. Marvin Wilson was convicted of beating Jerry Williams, a police informant, and then shooting him in the head and neck at close range in November 1992. Wilson’s lawyers said their client has a low IQ of 61 and never progressed beyond the elementary-school level in reading and math. In 2002, the Supreme Court ruled that mentally deficient defendants couldn’t be put to death, but left it up to the states to determine the threshold.