Updated

According to prosecutors, Joaquin Shadow Rams had grown accustomed to living off the life insurance proceeds of dead family members. So when the money ran out, he turned to his 1-year-old son to cash in again.

Rams' murder trial began Monday in Prince William Circuit Court, more than four years after 1-year-old Prince McLeod Rams died on a court-ordered, unsupervised visit with his father.

In the years since Prince's death in October 2012, the case has taken a remarkable number of twists, including conflicting rulings from medical examiners on the cause of Prince's death and a unique arrangement between prosecutors and the defense that took a potential death penalty off the table in exchange for Rams waving his right to a jury trial. A judge will now decide Rams' guilt or innocence.

Prosecutors say Rams drowned his son after taking out more than $500,000 in life insurance on the boy. Rams maintains his innocence and says Prince died after suffering a fever-related seizure.

In opening statements Monday, Prosecutor James Willett told the judge that Rams "had firsthand experience" which life insurance payouts, receiving a $162,000 payment after his mother, Alma Collins, died in 2008.

Indeed, prosecutors now suspect Rams was responsible for his mother's death, even though it was ruled a suicide. And they suspect he killed his former girlfriend, Shawn Mason, in 2003 — prosecutors say he tried unsuccessfully to collect on a life insurance policy after Mason was shot and killed.

A judge, though, ruled that evidence about the deaths of Collins and Mason cannot be introduced at Prince's trial, though Willett referred to Collins' death obliquely during opening statements.

But the case against Rams has holes. Most glaringly, the state's chief medical examiner overruled an initial finding that Prince died by drowning. Prince's official cause of death is now listed as undetermined. Both sides plan to present medical experts with dueling conclusions about how Prince died.

Defense lawyers said Monday that Rams was a loving father, and that witnesses saw him playing with the boy and doting on him the day he died.

The key witness Monday was Rams' older son and Prince's half brother, Joaquin Rams Jr, who goes by Shadow. The boy, now 17, testified that he was sharing a bedroom with Prince the day he died.

Shadow said he was playing video games on his computer while Prince slept in a crib. He testified that his dad poked his head in to check on the toddler a couple of times. Then, Shadow said, his dad burst into the room and scooped up Prince, even though Shadow saw no evidence that his baby brother was in distress.

"He was acting like Prince was dying," Shadow testified.

Rams took Prince into the bathroom and starting running water. Rams has said he splashed cold water on the boy in an effort to revive him. Prosecutors say he drowned the boy.

Prince's death occurred on just the fourth unsupervised visit that he had with his father. The boy's mother, Hera McLeod, unsuccessfully fought to deny Rams unsupervised visitation, saying she feared for her son's safety.

Rams faces life in prison if convicted.