Assistant State's Attorney Gina Cirincion concluded her case Thursday after questioning a handwriting expert, a used car dealer and a motel maintenance man.
Stanley did not take the stand, and defense attorney Stephen Tully didn't call any witnesses.
The jury began deliberating at 1:40 p.m. and concluded for the day at 4:30 p.m.
In her closing argument, Cirincion said Stanley should be convicted of first-degree murder because of the length and ferocity of the beating that killed Messersmith.
Cirincion went through a timeline of events starting with the first meeting of Stanley's cousin, Liger Grady, with Messersmith.
Grady, who operated a home improvement business, previously had done work for Messersmith and returned to his home Dec. 5, 2000 to tar his driveway, she said. Stanley accompanied Grady, who stood by as Stanley beat Messersmith, Cirincion argued.
The men took Messersmith's money, split it and both bought cars the next day, she said.
In August 2001, Grady pleaded guilty to second-degree murder in the case. His 20-year sentence was reduced to 10 years in exchange for his testimony.
Tully, in his closing argument, told the jury that the prosecution's case was based on the testimony of a man whose whole life is a lie.
Grady made his living by scamming the elderly into paying for overpriced, poorly performed home improvement work, he said.
Tully said Grady used aliases and changed his phone numbers regularly in the course of doing business.
"If you believe Grady I'd like to see you outside the courtroom after the case is over. I have some Enron stock I'd like to sell," he said.
Grady's testimony was the only direct evidence linking Stanley to the scene, Tully told the jury.
On Wednesday, Boone threw out evidence of Stanley's DNA found on a cigarette in Messersmith's yard because the defense hadn't had time to complete independent testing.
Cirincion said Grady lied in the past but his testimony should be believed because it was corroborated in several instances. He was consistent and maintained his composure, she said.
"When you are prosecuting a plot hatched in hell don't expect angels for witnesses," said Cirincion, invoking an old legal saying.
Cirincion said Liger testified that he drove around Clear Spring with Stanley the day Messersmith was beaten and sprayed another man's driveway before going to Messersmith's.
The homeowner testified that Grady and another man was at his home doing the work.
Grady also said he and Stanley stopped at a gas station in Clear Spring and bought food, gloves and duct tape.
A receipt from that gas station dated Dec. 5, 2000, was found in Grady's pickup truck. A fingerprint expert said Stanley's finger and palm prints were on the receipt.
Cirincion noted that Grady said he used the phone at Messersmith's home and a woman picked up on the line as he tried to dial.
Messersmith's girlfriend, Mary Royce, testified that she called Messersmith on Dec. 5, 2000 and a man she didn't know picked up the line before she hung up.
Grady testified that an enraged Stanley beat Messersmith, hitting him repeatedly in the head.
A medical examiner's report showed that Messersmith was hit at least 15 times, with most of the blows falling on his head. His neck and ribs were broken and four teeth were knocked out, Cirincion said.
Tulley argued that Grady was pointing the finger at Stanley to take attention away from himself. Maybe Grady or a relative of his committed the murder, he said.
Tully called Cirincion's case a "shell game" to confuse the jury into thinking Stanley was guilty.
"We all agree that Mr. Grady is a con man. Don't let him con you, too," said Tully.