WARWICK — James Richardson’s adult children testified yesterday — the day after his birthday — to establish his alibi and detail his travel plans, as Richardson’s trial in the killing of Margaret Duffy-Stephenson continued.

His daughter, Jamie, and son, Robert, both took the stand yesterday. Richardson, 40, is accused of murdering Duffy-Stephenson, 37, of Warwick. She was found dead on Nov. 18, 2005, days after she returned from a family vacation to Florida. Duffy-Stephenson worked as a teacher’s aide for special-education students at Archie R. Cole Junior High School in East Greenwich.

The police have said that Duffy-Stephenson was killed sometime during the night of Nov. 16, or the morning of Nov. 17, 2005.

When Robert Richardson got home from work on Nov. 16, 2005, he said his father was at the Cranston home they shared with his grandparents at the time. Robert Richardson watched a movie, Fever Pitch, with his girlfriend and his father watched a bit of it with them before heading back upstairs. Richardson checked on his dad after the movie ended and said he found his father asleep in an upstairs bedroom.

However, in the statement Richardson made to police weeks after the slaying, he told officers his father was on the Internet when he went upstairs. When pressed, Richardson told the court that he’d gotten the days mixed up and didn’t bother to correct the police when he was notified by his grandmother of the mistake.

“Some days he’s on the computer, other days he’s sleeping,” Richardson said. “I go and talk to him for a little before bed. . . . I didn’t think it mattered [that he mixed up the days] at that time,” Richardson testified.

Richardson’s name came up as the police began investigating the killing, Warwick police Detective Timothy Grant said. But officials had another suspect at the beginning of the case: James O. Stephenson III, Duffy-Stephenson’s husband.

“In a homicide such as this, in training we are taught to always take a look at the surviving spouse,” Grant testified. “That was done right off the bat.”

Stephenson’s alibi — that he was visiting family members in Florida — checked out via phone records and photographs, Grant said. But the police continued to look at him as a potential conspirator because of the friendship he and Richardson shared, Grant said. Richardson worked for Stephenson’s landscaping business and occasionally spent time with the family.

Jamie Richardson said she got a call before 8 a.m. on Nov. 18, 2005.

Her father was calling to ask her to buy a $2,620.70 ticket to the Philippines for him since he had neither a credit card nor a banking account. Richardson testified that her father said he would give her the money to deposit into her account and they would then use her debit card to buy the ticket from Northwest Airlines online.

Earlier that year, Richardson traveled to Manila to marry a woman he met on the Internet. His wife, now pregnant, was having complications, Jamie Richardson said. On the morning they went to Coastway Credit Union to make the deposit, Jamie Richardson learned her stepmother was vomiting blood, she said.

The stack of bills her father gave her was small, in mostly $100 and $20 bills, she told the court. They returned to Jamie Richardson’s Warwick home to buy the plane ticket online. He planned to leave the next day.

Her father never took that trip.

Later that day, he would be interviewed by Warwick police detectives investigating Duffy-Stephenson’s killing. He remained in the police station until evening before returning home.

Around 10 that night, Jamie Richardson got another call.

Her father, she testified, was crying hysterically as he looked at pictures of a camping trip he’d taken with the Stephensons.

“I stayed with him until midnight,” Richardson testified. “He was crying. He didn’t know what to do with himself.”

Richardson testified she told her father to call Stephenson to see if he needed anything. Her father tried calling and paging him, but never got through, she said.

tbuford@projo.com