A 35-year-old man was convicted of killing his mother and half-brother in Prince George’s circuit court Nov. 1, following a seven-day jury trial that divulged hundreds of articles of evidence and numerous witness testimonies.
Quindell Glen Mercer, of no fixed address, was found guilty of two counts of second-degree murder in the Aug. 4 slaying of Patricia Harris, 56, and Frank Lamar Harris, 20, who were gunned down inside their Fort Washington home. Mercer could be sentenced to up to 110 years in prison.
Prosecutors called the fatal incident an “execution” and applauded the jury’s verdict.
“Mr. Mercer executed his mother and stepbrother in cold blood for no apparent reason, and there is no excuse for this senseless act of violence that took the lives of two of our citizens,” State’s Attorney Angela Alsobrooks said in a statement. “I am pleased that a jury has held him accountable for his actions and that he will never have the chance to hurt anyone again.”
According to evidence presented in the trial, Mercer went to Patricia Harris’ home in the 11800 block of Hickory Drive where he shot her and his half-brother, and then posed their bodies on a sofa to make it look like they were sleeping. Their bodies were later discovered by Frank Arthur Harris, the victims’ husband and father.
Mercer was arrested 18 days after the victims’ bodies were discovered. Police have said their investigation led officers to a District Heights apartment where they found Mercer tossing a bag of handguns out of a window before being taken into custody Aug. 22.
During the trial, prosecutors said DNA evidence matched Mercer to the bag and several guns found inside the bag, including a 45-caliber Desert Eagle, the weapon prosecutors said was the murder weapon.
While a motive was never determined in the trial, Assistant State’s Attorney Aaron Meyers told the jury the killings may have been linked to a family dispute that involved family members telling Mercer he was becoming a bad influence on the younger son, Frank Lamar Harris.
“It’s hard to explain any murder, any execution. It just doesn’t make sense, especially in this case where it’s a mother and a brother,” Meyers told the jury in closing arguments Nov. 1. “Patricia and Lamar, they deserve justice ... And Mr. Mercer deserves justice.”
According to the state’s attorney’s office, Mercer was tied to the crime by an FBI handwriting expert, who linked Mercer to a number of items with handwriting found inside the bag, and DNA evidence that showed the possibility of the handgun used in the crime belonging to someone other than Mercer was 362 trillion to one.
Alan D’Appolito, Mercer’s defense attorney, said there was not enough clear evidence to show that Mercer was responsible for the murders.
“There was not a single fingerprint on the hundreds of items of evidence,” D’Appolito said, while acknowledging the fingerprints on one of the magazines for a handgun. “The state has proven there is reasonable doubt in their own case by the evidence. There is reasonable doubt. Mercer had absolutely no motive to do so in shooting his mother and brother.”
Fort Washington resident Rosa Winborne, who identified herself outside the courtroom as Patricia Harris’ first cousin, said it has been a struggle for the family to overcome the incident and family members have had difficulty determining a motive.
“I don’t know what to say. This has been pretty rough on the family,” she said. “I couldn’t believe [Mercer] had done that. He was never the type of person to do those things. Whatever led him to do this, I can’t imagine. I guess he was with the wrong crowd.”
Mercer was indicted on two counts of first-degree murder Sept. 20 but the jury only found him guilty of the lesser second-degree offenses, said John Erzen, a spokesman for the state’s attorney’s office.
“Obviously the state had very good DNA evidence and an FBI handwriting expert, but it was hard to establish a motive other than perhaps there was jealousy of some sort,” Erzen said.
In addition to two counts of second-degree murder, Mercer was also found guilty of using a handgun to commit a felony crime.
Mercer will be sentenced Jan. 11, according to online circuit court records.